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Yet Another GFN-131072 Mega Prime!
On 15 July 2017, 21:04:54 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

46776558^131072+1

The prime is 1,005,326 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 24th for Generalized Fermat primes and 240th overall.

The discovery was made by Giles Averay-Jones (Dingo) of Australia using an AMD Radeon 7700 series GPU in an Intel(R) Core(TM) i7-4771 CPU at 3.60GHz with 16GB RAM, running Microsoft Windows 10 Core Edition. This GPU took about 41 minutes to probable prime (PRP) test with GeneferOCL2. Giles is a member of the BOINC@AUSTRALIA team.

The prime was verified on 15 July 2017, 22:10:39 UTC by Dirk Sellsted (Dirk Sellsted) of Canada using an Nvidia Geforce GTX 1080 Ti GPU in an AMD Ryzen 7 1800X CPU with 32GB RAM, running Microsoft Windows 10 Core Edition. This GPU took about 6 minutes to probable prime (PRP) test with GeneferOCL2.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 7 Ultimate Edition. This computer took about 2 hours 45 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
17 Jul 2017 | 10:31:20 UTC · Comment


Another GFN-131072 Mega Prime!
On 10 July 2017, 08:34:34 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

46736070^131072+1

The prime is 1,005,277 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 24th for Generalized Fermat primes and 240th overall.

The discovery was made by Tom Greer (tng*) of the United States using an NVidia GeForce GTX 1080 GPU in an Intel(R) Core(TM) i7-6850K CPU at 3.60GHz with 16GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 15 minutes to probable prime (PRP) test with GeneferOCL2. Tom is a member of the Sicituradastra. team.

The prime was verified on 11 July 2017, 04:33:58 UTC by Thomas Midle (BoSoxFan86) of the United States using an AMD Radeon R7 M270 GPU in an Intel(R) Core(TM) i7-5500U CPU @ 2.40GHz with 12GB RAM, running Microsoft Windows 10 Core Edition. This GPU took about 2 hours 7 minutes to probable prime (PRP) test with GeneferOCL2. Thomas is a member of the Gridcoin team.

The PRP was confirmed prime by an Intel(R) Xeon (R) E5-2670 CPU CPU @ 2.60GHz with 32GB RAM, running Linux. This computer took about 15 hours 20 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
12 Jul 2017 | 20:36:08 UTC · Comment


GFN-131072 Mega Prime!
On 9 July 2017, 15:35:22 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

46730280^131072+1

The prime is 1,005,270 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 24th for Generalized Fermat primes and 240th overall.

The discovery was made by Jochen Beck (dh1saj) of Germany using an NVIDIA GeForce GTX 1060 in an Intel(R) Core(TM)2 Quad Q9550 CPU at 2.83GHz with 10GB RAM, running Microsoft Windows 7 Professional Edition. This GPU took about 13 minutes to probable prime (PRP) test with GeneferOCL2. Jochen is a member of the SETI.Germany team.

The prime was verified on 9 July 2017, 16:05:01 UTC by Ráďa Plšák (Plšák Ráďa) of the Czech Republic using an NVIDIA GeForce GTX 1050 Ti in an AMD FX(TM) 8320 with 16GB RAM, running Microsoft Windows 10 Core Edition. This GPU took about 34 minutes to probable prime (PRP) test with GeneferOCL2. Ráďa is a member of the Czech National Team.

The PRP was confirmed prime by an Intel(R) Xeon(R) E5-2670 CPU @ 2.60GHz with 32GB RAM, running Linux. This computer took about 15 hours 18 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
11 Jul 2017 | 0:41:28 UTC · Comment


GFN-262144 Mega Prime!
On 30 June 2017, 02:54:43 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

3060772^262144+1

The prime is 1,700,222 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 5th for Generalized Fermat primes and 50th overall.

The discovery was made by Sean Humphries (No.15) of the United States using an NVIDIA GeForce GTX 1080 in an Intel(R) Xeon(R) E5-2670 CPU at 2.60GHz with 32GB RAM, running Linux. This GPU took about 16 minutes to probable prime (PRP) test with GeneferOCL3. Sean is a member of the Overclock.net team.

The prime was verified on 1 July 2017, 18:49:46 UTC by John Hall (JH30895) of the United States using an NVIDIA GeForce GTX 680 in a dual Intel(R) Xeon(R) X5680 CPU @ 3.33 GHz with 24GB RAM, running macOS Sierra. This GPU took about 52 minutes to probable prime (PRP) test with GeneferOCL5. John is a member of the Ars Technica team.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 4 hours 18 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
5 Jul 2017 | 13:24:53 UTC · Comment


Urgent: Enable Prime Reporting Before It's Too Late
We say it all the time, but now you can lose out if you don't have prime reporting enabled.

SGS primes are currently only on the T5K list for a few days before falling off the list. If you do not have prime reporting enabled, there may be no time to contact you before it's too late to report your prime. Rather than let the prime go unreported, we will report SGS primes under the DCer's name if you don't have prime reporting enabled. If the DCer also doesn't have prime reporting enabled, we will report the prime anonymously. The alternative is that the prime doesn't get reported at all.

For more details and discussion please see the 4888 thread in our Sophie Germain Prime Search topic.

To enable prime reporting, please go to "Your account" on the menu on the left, then select "PrimeGrid Preferences". Scroll down a bit to where it says "Primary (default) preferences:" and select "Edit PrimeGrid Preferences".

Scroll down to "Reporting primes to the Prime Pages" and click the two checkboxes for granting permission to report primes and to send you an email when a prime is found. You must enter your real name. T5K will not accept fake names or user names. Please enter your name as "given-name surname". (Note that even in cultures where the surname is normally put first, we need the given name first and the surname last.)

If for any reason you don't want us to use your name, we can report anonymously for you -- just check the permission box and enter something like "report anonymously" in the name box.

Finally, scroll down to the bottom and click on the "Update preferences" button.
2 Jul 2017 | 18:55:10 UTC · Comment


Another PPS-Mega Prime!
On 20 June 2017, 17:28:20 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
953*2^3405729+1

The prime is 1,025,230 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 201st overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz with 8GB RAM, running Linux. This computer took about 1 hour 14 minutes to complete the primality test using LLR.

The prime was verified on 24 June 2017 06:23:26 UTC, by Jon Goral ([KWSN]John Galt 007) of the United States using an Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz with 10GB RAM, running Microsoft Windows 10 Core Edition. This computer took about 5 hours 54 minutes to complete the primality test using LLR. Jon is a member of The Knights Who Say Ni! team.

For more details, please see the official announcement.
26 Jun 2017 | 12:24:58 UTC · Comment


Finally, Another PPS-Mega Prime!
On 13 June 2017, 10:46:25 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

833*2^3403765+1

The prime is 1,024,639 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 202nd overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz with 8GB RAM, running Linux. This computer took about 1 hour 21 minutes to complete the primality test using LLR.

The prime was verified on 13 June 2017, 16:05:06 UTC by Michael Bowe (No_Name) of Germany using an Intel(R) Xeon(R) E3-1230 v5 CPU @ 3.40GHz with 32GB RAM, running Microsoft Windows Server 2012 R2 Foundation Edition. This computer took about 1 hour 24 minutes to complete the primality test using LLR. Michael is a member of the SETI.Germany team.

For more details, please see the official announcement.
14 Jun 2017 | 12:50:32 UTC · Comment


Yet Another GFN-131072 Mega Prime!
On 4 June 2017, 04:02:39 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

46413358^131072+1

The prime is 1,004,883 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 23rd for Generalized Fermat primes and 235th overall.

The discovery was made by Sagi Iltus (sagiil) using an Intel(R) Xeon(R) E5-2673 v3 CPU at 2.40GHz with 8GB RAM, running Linux. This CPU took about 7 hours 4 minutes to probable prime (PRP) test with Genefer.

The prime was verified on 7 June 2017, 18:18:37 UTC by Dirk Broer (Dirk Broer) of the British Virgin Islands using an AMD Athlon(TM) 5350 APU with 16GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 4 hours 1 minute to probable prime (PRP) test with GeneferOCL2. Dirk is a member of the AMD Users team.

The PRP was confirmed prime by an Intel(R) Xeon (R) E5-2670 CPU CPU @ 2.60GHz with 32GB RAM, running Linux. This computer took about 15 hours 21 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
7 Jun 2017 | 19:24:18 UTC · Comment


Another GFN-131072 Mega Prime!
On 31 May 2017, 09:22:45 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

46385310^131072+1

The prime is 1,004,848 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 23rd for Generalized Fermat primes and 235th overall.

The discovery was made by Matt Jurach (mattozan) of the United States using an AMD Pitcairn GPU in an Intel(R) Core(TM) i7-5820K CPU at 3.30GHz with 16GB RAM, running Microsoft Windows 7 Enterprise Edition. This GPU took about 42 minutes to probable prime (PRP) test with GeneferOCL2. Matt is a member of the Aggie The Pew team.

The prime was verified on 31 May 2017, 22:53:40 UTC by Krzysztof Ostaszewski (Krzysiak_PL_GDA) of Poland using an AMD R9 Fury Series GPU in an Intel(R) Xeon(R) E5-2683 v3 CPU at 2.00GHz with 32GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 11 minutes to probable prime (PRP) test with GeneferOCL2. Krzysztof is a member of the BOINC@Poland team.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 2 hours 52 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
1 Jun 2017 | 10:32:06 UTC · Comment


GFN-131072 Mega Prime!
On 29 May 2017, 07:16:40 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

46371508^131072+1

The prime is 1,004,831 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 23rd for Generalized Fermat primes and 235th overall.

The discovery was made by Mike Kinney (Mektacular) of the United States using an NVIDIA GeForce GTX 950 in an Intel(R) Xeon(R) E5-2670 CPU at 2.60GHz with 64GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 21 minutes to probable prime (PRP) test with GeneferOCL2. Mike is a member of the Crunching@EVGA team.

The prime was verified on 29 May 2017, 14:11:46 UTC by Matt Jurach (mattozan) of the United States using an NVIDIA GeForce GTX 460 in an Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz with 8GB RAM, running Microsoft Windows 7 Ultimate Edition. This GPU took about 36 minutes to probable prime (PRP) test with GeneferOCL2. Matt is a member of the Aggie The Pew team.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 2 hours 41 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
30 May 2017 | 11:20:48 UTC · Comment


Another PPS Mega Prime!
On 27 May 2017, 18:34:13 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
1167*2^3399748+1

The prime is 1,023,430 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 202nd overall.

The discovery was made by Eric Eskam (Doc No) of the United States using an Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz with 8GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 1 hour 17 minutes to complete the primality test using LLR. Eric is a member of the Heinlein Fans team.

The prime was verified on 27 May 2017, 20:33:53 UTC by Amy Chambers (Buckeye74) of the United States using an Intel(R) Core(TM) i7-4770K CPU @ 3.50GHz with 16GB RAM, running Microsoft Windows 10 Core Edition. This computer took about 1 hour 15 minutes to complete the primality test using LLR. Amy is a member of the Sigma Omicron Chapter of Tau Kappa Epsilon team.

For more details, please see the official announcement.
30 May 2017 | 11:13:29 UTC · Comment


Why Not? Another PPS-Mega Prime!
On 22 May 2017 21:53:30 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

611*2^3398273+1

The prime is 1,022,985 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 202nd overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 @ 3.30GHz with 8GB RAM, running Linux. This computer took about 1 hour 18 minutes to complete the primality test using LLR.

The prime was verified on 24 May 2017 04:17:13 UTC by Luis DeJesus (lajjr) of the United States using an Intel(R) Core(TM) i7-4510U @ 2.00GHz with 16GB RAM, running Microsoft Windows 10 Core Edition. This computer took about 5 hours 10 minutes to complete the primality test using LLR. Luis is a member of the Latinos Aqui team.

For more details, please see the official announcement.
24 May 2017 | 11:33:41 UTC · Comment


Another PPS-Mega Prime!
On 29 April 2017 14:06:48 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

609*2^3392301+1

The prime is 1,021,188 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 205th overall.

The discovery was made by User “jimmy” of Belgium using an Intel(R) Core(TM) i7-4790 @ 3.60GHz with 12GB RAM, running Microsoft Windows 10 Core Edition. This computer took about 1 hour 36 minutes to complete the primality test using LLR.

The prime was verified on 30 April 2017 11:22:53 UTC by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 @ 3.30GHz with 8GB RAM, running Linux. This computer took about 1 hour 14 minutes to complete the primality test using LLR.

For more information, please see the official announcement.
22 May 2017 | 12:55:23 UTC · Comment


Another PPS-Mega Prime!
On 12 May 2017, 19:12:52 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

1049*2^3395647+1

The prime is 1,022,195 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 203rd overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 4GB RAM, running Microsoft Windows 7 Enterprise Edition. This computer took about 1 hour 36 minutes to complete the primality test using LLR.

The prime was verified on 14 May 2017 09:32:20 UTC, by Sven Lünser (TheWickedSvene) of Germany using an AMD Phenom(TM) II X6K 1100T CPU with 16GB RAM, running Linux. This computer took about 2 hours 43 minutes to complete the primality test using LLR. Sven is a member of the Rechenkraft.net team.

For more dtails, please see the official announcement.
14 May 2017 | 13:10:52 UTC · Comment


WSS and Wieferich Searches Suspended
The PRPNet Wall-Sun-Sun and Wieferich projects have been suspended. Please click here for more information and discussion. 11 May 2017 | 12:01:57 UTC · Comment


Yet Another PPS-Mega Prime!
On 3 May 2017, 19:30:03 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

555*2^3393389+1

The prime is 1,021,515 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 203rd overall.

The discovery was made by Douglas B. McKay (KD7LRJ) of the United States using an Intel(R) Core(TM) i7-4790K CPU @ 4.00 GHz with 32GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 1 hour 15 minutes to complete the primality test using LLR. Douglas is a member of the Aggie The Pew team.

The prime was verified on 3 May 2017 20:11:14 UTC, by John Murphy (TheDawgz) of the United States using an Intel Virtual CPU with 1GB RAM, running Linux. This computer took about 1 hour 24 minutes to complete the primality test using LLR. John is a member of the Aggie The Pew team.

For more details, please see the official announcement.
5 May 2017 | 13:36:25 UTC · Comment


Another PPS-Mega Prime!
On 28 April 2017, 04:22:38 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

805*2^3391818+1

The prime is 1,021,042 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 204th overall.

The discovery was made by Reiner Elgetz (reiner) of Germany using an AMD Ryzen 7 1700 with 16GB RAM, running Linux. This computer took about 21 minutes to complete the primality test using LLR with 8 threads. Reiner is a member of the Planet 3DNow! team.

The prime was verified on 28 April 2017 13:44:43 UTC, by William Finn (W.L.F.) of the United States using an Intel(R) Core(TM) i7-5820K CPU @ 3.30GHz with 24GB RAM running Microsoft Windows 10 Professional Edition. This computer took about 1 hour 36 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
1 May 2017 | 16:02:04 UTC · Comment


GFN-131072 Mega Prime!
On 26 April 2017, 17:34:00 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

46077492^131072+1

The prime is 1,004,469 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 23rd for Generalized Fermat primes and 230th overall.

The discovery was made by Jeffrey Mangio (Novanglus) of the United States using an NVIDIA GeForce GTX 1080 in an Intel(R) Core(TM) i5-4690K CPU at 3.50GHz with 16GB RAM, running Microsoft Windows 10 Core Edition. This GPU took about 9 minutes to probable prime (PRP) test with GeneferOCL4. Jeffrey is a member of the SETI.USA team.

The prime was verified on 27 April 2017, 13:33:00 UTC by Osamu Andou (o-ando) of Japan using an NVIDIA GeForce GTX 1060 in an Intel(R) Core(TM) i7-6700 CPU at 3.40GHz with 16GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 13 minutes to probable prime (PRP) test with GeneferOCL4.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 1 hour 29 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
1 May 2017 | 15:54:26 UTC · Comment


New sub-project: GCW-LLR
We have opened up a new subproject, GCW-LLR. It is a CPU-only project. Task sizes are initially very small, but I expect them to grow in size fairly rapidly. There is a new set of badges for the GCW-LLR project.

Please see this thread in the GCW forum for more details and discussion.
29 Apr 2017 | 16:05:11 UTC · Comment


Action may be required: TRP-Sieve is now shut down.
The TRP Sieve project has come to an end, and work generation for that subproject has stopped. While there will be a few recycled tasks available for a short time, eventually they will all be gone.

If TRP-Sieve is the only PrimeGrid subproject you're running, you should select another of our subprojects to run. We suggest GCW-Sieve. It's very similar to TRP-Sieve.

Since TRP-Sieve previously was automatically assigned to new users, if you've never explicitly selected which subproject to run, there's a good chance your computer is currently configured to TRP-Sieve. Please go to the PrimeGrid preferences page to change your preferences.

For discussion and more information, please see this forum thread.
25 Apr 2017 | 13:54:01 UTC · Comment


Another PPS-Mega Prime!
On 23 April 2017, 22:31:40 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

663*2^3390469+1

The prime is 1,020,636 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 205th overall.

The discovery was made by Rolf Henrik Nilsson (puh32) of Sweden using an Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz with 16GB RAM, running Microsoft Windows 10 Core Edition. This computer took about 49 minutes to complete the primality test using LLR.

The prime was verified on 24 April 2017 11:04:31 UTC, by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 8GB RAM running Linux. This computer took about 1 hour 8 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
25 Apr 2017 | 0:01:21 UTC · Comment


Celebrate Mathematics Awareness Month with PrimeGrid!
Please join PrimeGrid in celebrating Mathematics Awareness Month by participating in our "Mathematics Awareness Month Challenge", beginning Friday, April 7th, at 12:00:00 UTC. Please note that this is 6 hours earlier than our nominal challenge starting time.

This challenge is being offered on the Prime Sierpinski Project (LLR), and will run for 15 days. We're currently running a double check of older PSP work, so the PSP tasks are currently much shorter than normal.

For more information, or to discuss the challenge, please see this thread on our forums.
6 Apr 2017 | 16:16:39 UTC · Comment


GFN-262144 Mega Prime!
On 22 March 2017, 09:33:58 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

2676404^262144+1

The prime is 1,684,945 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 5th for Generalized Fermat primes and 52nd overall.

The discovery was made by Wolfgang Schwieger (DeleteNull) of Germany using an NVIDIA GeForce GTX 1070 in an Intel(R) Core(TM) i7-6700K CPU at 4.00GHz with 16GB RAM, running Linux. This GPU took about 16 minutes to probable prime (PRP) test with GeneferOCL4. Wolfgang is a member of the SETI.Germany team.

The prime was verified on 22 March 2017, 23:16:34 UTC by William de Thomas (wdethomas) of Puerto Rico using an NVIDIA GeForce GTX Titan X in an Intel(R) Core(TM) i7-4790K CPU at 4.00GHz with 16GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 18 minutes to probable prime (PRP) test with GeneferOCL4. William is a member of the Puerto Rico Assisting Science team.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 8 hours 40 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
23 Mar 2017 | 13:26:26 UTC · Comment


GFN-131072 Mega Prime!
On 18 March 2017, 21:52:24 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

45570624^131072+1

The prime is 1,003,840 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 22nd for Generalized Fermat primes and 231st overall.

The discovery was made by Vince Splain (yank) of The United States using an NVIDIA GeForce GTX 980 in an Intel(R) Core(TM) i7-5960X CPU at 3.00GHz with 16GB RAM, running Microsoft Windows 7 Professional Edition. This GPU took about 14 minutes to probable prime (PRP) test with GeneferOCL4. Vince is a member of the US Navy team.

The prime was verified on 20 March 2017, 03:07:07 UTC by Brett Melvold (AgentQ) of Australia using an AMD R9 Fury Series GPU in an Intel(R) Core(TM) i7-5820K CPU at 3.30GHz with 32GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 25 minutes to probable prime (PRP) test with GeneferOCL4. Brett is a member of the BOINC@AUSTRALIA team.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 2 hours 38 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
19 Mar 2017 | 17:46:15 UTC · Comment


Yet Another PPS-Mega Prime!
On 14 March 2017 14:01:17 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
621*2^3378148+1

The prime is 1,016,927 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 205th overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 @ 3.30GHz with 8GB RAM, running Linux. This computer took about 1 hour 2 minutes to complete the primality test using LLR.

The prime was verified on 14 March 2017 14:09:41 UTC by Lars Fricke (Lars Fricke) of Germany using an Intel(R) Xeon(R) E5-2660v3 @ 2.60GHz with 128GB RAM, running Linux. This computer took about 1 hour 10 minutes to complete the primality test using LLR. Lars is a member of the Rechenkraft.net team.

For more details, please see the official announcement.
15 Mar 2017 | 15:15:08 UTC · Comment


Another PPS-Mega Prime!
On 14 March 2017 09:23:13 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
1093*2^3378000+1

The prime is 1,016,883 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 205th overall.

The discovery was made by Andreas Rohmann (Andreas Rohmann) of Germany using an Intel(R) Core(TM) i7-4771 @ 3.50GHz with 32GB RAM, running MacOS. This computer took about 2 hours 28 minutes to complete the primality test using LLR.

The prime was verified on 14 March 2017 16:51:12 UTC by Wolfgang Schwieger (DeleteNull) of Germany using an Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz with 64GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 1 hour 30 minutes to complete the primality test using LLR. Wolfgang is a member of the SETI.Germany team.

For more details, please see the official announcement.
15 Mar 2017 | 14:57:06 UTC · Comment


PPS-Mega Prime!
On 12 March 2017 18:28:04 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
861*2^3377601+1

The prime is 1,016,763 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 205th overall.

The discovery was made by Mike Kinney (Mektacular) of the United States using an Intel(R) Core(TM) i5-6500 @ 3.20GHz with 16GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 53 minutes to complete the primality test using LLR. Mike is a member of the Crunching@EVGA team.

The prime was verified on 12 March 2017 18:47:34 UTC by Stefan Geiger (Steve) of Austria using an Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz with 16GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 52 minutes to complete the primality test using LLR. Stefan is a member of the Aggie The Pew team.

For more details, please see the official announcement.
15 Mar 2017 | 13:42:40 UTC · Comment


GFN-262144 Mega Prime!
On 11 March 2017, 18:07:33 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

2611204^262144+1

The prime is 1,682,141 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 5th for Generalized Fermat primes and 52nd overall.

The discovery was made by Roman Vogt (Tabaluga) of Germany using an NVIDIA GeForce GTX 580 in an Intel(R) Core(TM) i7-2700K CPU @ 3.50GHz with 8GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 46 minutes to probable prime (PRP) test with GeneferOCL4. Roman is a member of the Sicituradastra. team.

The prime was verified on 12 March 2017, 12:13:28 UTC by Markus Tervooren (mtervooren) of Germany using an AMD Ellesmere GPU in an AMD Phenom(tm) II X6 1090T with 8GB RAM, running Linux. This computer took about 29 minutes to complete the probable prime (PRP) test.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Windows 10 Professional Edition. This computer took about 7 hours 28 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
13 Mar 2017 | 12:23:47 UTC · Comment


GFN-262144 Mega Prime!
On 24 February 2017, 07:16:40 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

2514168^262144+1

The prime is 1,677,825 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 5th for Generalized Fermat primes and 52nd overall.

The discovery was made by William de Thomas (wdethomas) of Puerto Rico using an NVIDIA GeForce GTX Titan X in an Intel(R) Core(TM) i7-4790K CPU at 4.00GHz with 16GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 18 minutes to probable prime (PRP) test with GeneferOCL4. William is a member of the Puerto Rico Assisting Science team.

The prime was verified on 24 February 2017, 12:21:21 UTC by Hans-Jürgen Bergelt (Hans-Jürgen Bergelt) of Germany using an NVIDIA GeForce GTX 690 in an Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz with 8GB RAM, running Microsoft Windows 10 Core Edition. This GPU took about 37 minutes to probable prime (PRP) test with GeneferOCL4. Hans-Jürgen is a member of the SETI.Germany team.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 8 hours 7 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
25 Feb 2017 | 16:34:39 UTC · Comment


TRP-Sieve ending soon (again!)
It took longer than we anticipated, but we're moving forward now with our plans to complete the TRP-Sieve. Our rough estimate is that it will take about a month or two to reach optimal sieving depth.

I suspect most folks already did their "final badge hunting" when we first announced this back in August and September, but if you want to push for that next TRP-Sieve badge, now is the time to do it!

More details and discussion can be found in this forum thread.
25 Feb 2017 | 13:14:17 UTC · Comment


GFN-131072 Mega Prime!
On 23 February 2017, 02:20:15 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:
45315256^131072+1

The prime is 1,003,520 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 20th for Generalized Fermat primes and 223rd overall.

The discovery was made by William Donovan (Williamd007) of the United States using an NVIDIA GeForce GTX 1070 in an Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz with 16GB RAM, running Microsoft Windows 10 Core Edition. This GPU took about 9 minutes to probable prime (PRP) test with GeneferOCL4. William is a member of The Knights Who Say Ni! team.

The prime was verified on 23 February 2017, 06:00:13 UTC by Andrea Tosatto (Andrea Tosatto - Italy) of Italy using an Intel(R) Core(TM)2 Duo CPU @ 3.00GHz with 2GB RAM, running Microsoft Windows 7 Professional Edition. This computer took about 9 hours 17 minutes to complete the probable prime (PRP) test.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Windows 10 Professional Edition. This computer took about 1 hour 17 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
23 Feb 2017 | 13:07:29 UTC · Comment


PPS-Mega Prime, Wednesday Edition
On 21 February 2017 08:08:07 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
839*2^3369383+1

The prime is 1,014,289 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 202nd overall.

The discovery was made by Robert Lacroix (composite) of Canada using an Intel(R) Core(TM) i7-5820K @ 3.30GHz with 16GB RAM, running Linux. This computer took about 1 hour 20 minutes to complete the primality test using LLR.

The prime was verified on 21 February 2017, 08:16:49 UTC by Eric Ueda (SlangNRox) of the United States using an Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 1 hours 40 minutes to complete the primality test using LLR. Eric is a member of the TeAm AnandTech team.

For more details, please see the official announcement.
22 Feb 2017 | 13:11:44 UTC · Comment


PPS-Mega Prime, Tuesday Edition
On 20 February 2017 14:39:06 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
677*2^3369115+1

The prime is 1,014,208 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 202nd overall.

The discovery was made by Wolfgang Schmidt (Artist) of Germany using an Intel(R) Core(TM) i7-4770 @ 3.40GHz with 16GB RAM, running Linux. This computer took about 54 minutes to complete the primality test using LLR. Wolfgang is a member of the Special: Off-Topic team.

The prime was verified on 21 February 2017, 15:15:01 UTC by Hans-Jürgen Bergelt (Hans-Jürgen Bergelt) of Germany using an Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz with 8GB RAM, running Microsoft Windows 7 Professional Edition. This computer took about 2 hours 26 minutes to complete the primality test using LLR. Hans-Jürgen is a member of the SETI.Germany team.

For more details, please see the official announcement.
21 Feb 2017 | 17:24:29 UTC · Comment


PPS-Mega Prime, Saturday Edition, Part Two
On 18 February 2017 11:07:35 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
715*2^3368210+1

The prime is 1,013,936 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 202nd overall.

The discovery was made by Daniel Frużyński (Daniel) of Poland using an Intel(R) Xeon(R) CPU E5-2670 @ 2.60GHz with 32GB RAM, running Linux. This computer took about 1 hour 54 minutes to complete the primality test using LLR. Daniel is a member of the BOINC@Poland team.

The prime was verified on 18 February 2017, 23:47:33 UTC by Mark Dodrill (mdodrill) of the United States using an Intel(R) Core(TM) i7-6700K CPU @ 3.40GHz with 32GB RAM, running Microsoft Windows 10. This computer took about 1 hour 38 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
20 Feb 2017 | 13:37:38 UTC · Comment


PPS-Mega Prime, Saturday Edition, Part One
On 18 February 2017 06:57:35 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
617*2^3368119+1

The prime is 1,013,908 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 202nd overall.

The discovery was made by Kimmo Koski (Cinclus) of Finland using an Intel(R) Core(TM) i7-4790 @ 3.60GHz with 24GB RAM, running Microsoft Windows 10 Core Edition. This computer took about 1 hour 42 minutes to complete the primality test using LLR. Kimmo is a member of the Aggie The Pew team.

The prime was verified on 18 February 2017, 09:31:18 UTC by Alen Kecic (Freezing) of Germany using an Intel(R) Core(TM) i5-4219M CPU @ 2.60GHz with 8GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 56 minutes to complete the primality test using LLR. Alen is a member of the SETI.Germany team.

For more details, please see the official announcement.
20 Feb 2017 | 13:30:01 UTC · Comment


PPS-Mega Prime, Friday Edition
On 17 February 2017 00:26:30 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
777*2^3367372+1

The prime is 1,013,683 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 202nd overall.

The discovery was made by Lars Fricke (Lars Fricke) of Germany using an Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz with 64GB RAM, running Linux. This computer took about 1 hour 34 minutes to complete the primality test using LLR.

The prime was verified on 17 February 2017, 17:55:08 UTC by Hans-Jürgen Bergelt (Hans-Jürgen Bergelt) of Germany using an Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 7 Home Premium Edition. This computer took about 1 hour 55 minutes to complete the primality test using LLR. Hans-Jürgen is a member of the SETI.Germany team.

For more details, please see the official announcement.
20 Feb 2017 | 13:21:03 UTC · Comment


Yes, Its Another PPS-Mega Prime!
On 9 February 2017, 17:56:42 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
533*2^3362857+1

The prime is 1,012,324 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 203rd overall.

The discovery was made by Hans-Jürgen Bergelt (Hans-Jürgen Bergelt) of Germany using an Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz with 8GB RAM, running Microsoft Windows 7 Ultimate Edition. This computer took about 1 hour 18 minutes to complete the primality test using LLR. Hans-Jürgen is a member of the SETI.Germany team.

The prime was verified on 10 February 2017, 00:06:03 UTC by Steve King (steveking) of the United States using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 20GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 1 hour 20 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
10 Feb 2017 | 22:17:40 UTC · Comment


Another PPS Mega Prime!
On 9 February 2017, 08:57:25 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
619*2^3362814+1

The prime is 1,012,311 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 203rd overall.

The discovery was made by Daniel Frużyński (Daniel) of Poland using an Intel(R) Xeon(R) CPU E5-2670 @ 2.60GHz with 32GB RAM, running Linux. This computer took about 1 hour 49 minutes to complete the primality test using LLR. Daniel is a member of the BOINC@Poland team.

The prime was verified on 9 February 2017, 09:18:53 UTC by Alen Kecic (Freezing) of Germany using an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 56 minutes to complete the primality test using LLR. Alen is a member of the SETI.Germany team.

For more details, please see the official announcement.
10 Feb 2017 | 16:41:36 UTC · Comment


Better Late Than Never: 2017 Tour de Primes!
PrimeGrid's annual Tour de Primes is underway!

Unlike other challenges, there's no trophy for participation. This challenge is all about finding prime numbers.

As with last year, there will also be a red jersey -- which will be awarded to whomever finds the largest prime number during the month of February.

And, of course, we'll be awarding the green, yellow, and polk-a-dot jerseys as in previous years.

For more information, please see Tour de Primes 2017.

Good luck everyone!
8 Feb 2017 | 13:52:59 UTC · Comment


GFN-131072 Mega Prime!
On 1 February 2017, 02:24:46 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

44919410^131072+1

The prime is 1,003,020 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 19th for Generalized Fermat primes and 215th overall.

The discovery was made by Vince Splain (yank) of The United States using an NVIDIA GeForce GTX 980 in an Intel(R) Core(TM) i7-5960X CPU at 3.00GHz with 16GB RAM, running Microsoft Windows 7 Professional. This GPU took about 14 minutes to probable prime (PRP) test with GeneferOCL4. Vince is a member of the US Navy team.

The prime was verified on 3 February 2017, 21:17:17 UTC by William Donovan (Williamd007) of the United States using an NVIDIA GTX 960 on an AMD FX(tm)-9590 CPU with 16GB RAM, running Microsoft Windows 10 Core Edition. This GPU took about 22 minutes to PRP test with GeneferOCL4. William is a member of The Knights Who Say Ni! team.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 5 hours 17 minutes to complete the primality test using LLR.

For more information, please see the official announcement.
1 Feb 2017 | 17:38:11 UTC · Comment


Another PPS Mega Prime!
On 19 January 2017, 22:43:32 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

1183*2^3353058+1

The prime is 1,009,375 digits long and will enter Chris Caldwell's “The Largest Known Primes Database” ranked 202nd overall.

The discovery was made by Michele T. Mazzucato (nillium) of Italy using an Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz with 8GB RAM, running Microsoft Windows 7 Professional Edition. This computer took about 2 hours 26 minutes to complete the primality test using LLR.

The prime was verified on 20 January 2017, 00:27:58 UTC by Akinori Kanno (teagin) of Japan using an Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 10 Professional Edition. This computer took about 2 hours 49 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
23 Jan 2017 | 13:59:24 UTC · Comment


ALERT: prothsearch.net is now prothsearch.com
The prothsearch.net domain has been stolen by a cybersquatter. The real website is being rebuilt at http://prothsearch.com. The squatter is using some content from the old website to make the new, fake website look "real". This is clearly an act of deception. It's unclear whether the squatter merely wants to use the site as clickbait for ads or wants to do something more nefarious such as distributing maleware. Either way, please avoid the old website, and please pass this information along to others in the prime search community. Thank you! 20 Jan 2017 | 6:45:55 UTC · Comment


PPS Mega Prime!
On 16 January 2017, 04:34:40 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

543*2^3351686+1

The prime is 1,008,961 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 201st overall.

The discovery was made by Simon Rawles (rawles) of the United Kingdom using an Intel(R) Core(TM) i7-5960X CPU @ 3.00GHz with 32GB RAM, running Linux. This computer took about 56 minutes to complete the primality test using LLR.

The prime was verified on 16 January 2017, 05:06:22 UTC by Ed Goforth (BlisteringSheep) of Saint Kitts and Nevis using an Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz with 64GB RAM, running Microsoft Windows Server 2012 R2. This computer took about 1 hour 35 minutes to complete the primality test using LLR. Ed is a member of the Christians team.

For more details, please see the official announcement.
17 Jan 2017 | 18:08:23 UTC · Comment


GFN-131072 Mega Prime!
On 11 December 2016, 02:52:40 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

44438760^131072+1

The prime is 1,002,408 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 19th for Generalized Fermat primes and 198th overall.

The discovery was made by Håkan Lind (sangis43) of Sweden using an NVIDIA GeForce GTX 960 in an Intel(R) Core(TM) i7-6800k CPU with 16GB RAM, running Microsoft Windows 10 Professional. This GPU took about 22 minutes to probable prime (PRP) test with GeneferOCL4. Håkan is a member of the Sicituradastra. team.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz with 16GB RAM, running Windows 7 Ultimate. This computer took about 8 hours 58 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
14 Dec 2016 | 11:56:21 UTC · Comment


Another PPS Mega Prime!
On 12 December 2016, 08:33:42 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
733*2^3340464+1

The prime is 1,005,583 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 191st overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz with 8GB RAM, running Linux. This computer took about 1 hour 14 minutes to complete the primality test using LLR.

The prime was verified on 13 December 2016, 05:33:05 UTC by Rafal Foryszewski (4ys) of Poland using an Intel(R) Pentium(R) Dual CPU E2160 @ 1.80GHz with 2GB RAM, running Microsoft Windows XP Professional. This computer took about 5 Hours 56 minutes to complete the primality test using LLR. Rafal is a member of the BOINC@Poland team.

For more details, please see the official announcement.
13 Dec 2016 | 14:33:49 UTC · Comment


AP26 Found!
On 11 December 2016, 20:06:09 UTC, PrimeGrid’s AP27 Search (Arithmetic Progression of 27 primes) found the progression of 26 primes:

142099325379199423+16549135*23#*n for n=0..25

The discovery was made by Koichi Soraku (JG4KEZ(Koichi Soraku)) of Japan using a NVIDIA GTX 1070 on an Intel(R) Core(TM) i7-5775C @ 3.30GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 27 minutes to process the task (each task tests 100 progression differences of 10 shifts each). Koichi is a member of the BOINC@MIXI team.

The progression was verified on 12 December 2016 10:44:25 UTC, by Dirk Kraemer (DoctorNow) of Germany using an NVIDIA GTX 760 on an AMD Phenom(tm) II X6 CPU running Microsoft Windows Vista. This computer took about 2 hours 22 minutes to process the task. Dirk is a member of the BOINC Confederation.

The AP26 will be listed in Jens Kruse Andersen's Primes in Arithmetic Progression Records page under the section(s):

All known AP24 to AP26

For all APs found 23 and greater, please see PrimeGrid's AP26 Statistics.

For more details, please see the official announcement.
12 Dec 2016 | 16:30:30 UTC · Comment


Another PPS Mega Prime!
On 3 December 2016, 16:11:01 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
651*2^3337101+1

The prime is 1,004,571 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 192nd overall.

The discovery was made by Konstantin Stanko (Pollux) of the Czech Republic using an Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz with 16GB RAM, running Microsoft Windows 7 Professional. This computer took about 1 hour 8 minutes to complete the primality test using LLR. Konstantin is a member of the Czech National Team.

The prime was verified on 3 December 2016, 16:24:31 UTC by Albert Symula (Albercik) of Poland using an Intel(R) Core(TM) i5-6600 @ 3.30GHz with 8GB RAM, running Microsoft Windows 10 Professional. This computer took about 57 minutes to complete the primality test using LLR. Albert is a member of the BOINC@Poland team.

For more details, please see the official announcement.
5 Dec 2016 | 13:03:49 UTC · Comment


PPS Mega Prime, 50th Mega Prime of the Year!
On 29 November 2016, 16:00:42 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
849*2^3335669+1

The prime is 1,004,140 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 193rd overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz with 8GB RAM, running Linux. This computer took about 1 hour 12 minutes to complete the primality test using LLR.

The prime was verified on 29 November 2016, 18:54:26 UTC by Ed Goforth (BlisteringSheep) of Saint Kitts and Nevis using an Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz with 48GB RAM, running Linux. This computer took about 1 hour 36 minutes to complete the primality test using LLR. Ed is a member of the Christians team.

For more details, please see the official announcement.
30 Nov 2016 | 14:07:25 UTC · Comment


GFN-131072 Mega Prime!
On 26 November 2016, 05:43:10 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

44330870^131072+1

The prime is 1,002,270 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 19th for Generalized Fermat primes and 196th overall.

The discovery was made by Eric Eskam (Doc No) of the United States using an NVIDIA GeForce GTX 580 in an Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz with 8GB RAM, running Microsoft Windows 10 Professional. This GPU took about 25 minutes to probable prime (PRP) test with GeneferOCL4. Eric is a member of the Heinlein Fans team.

The was verified on 29 November 2016, 00:17:19 UTC by Brent Schneider (KWSN-SpongeBob SquarePants) of Nepal using an NVIDIA Quadro 4000 in an Intel(R) Xeon(R) W3960 CPU @ 3.47GHz with 12GB RAM, running Microsoft Windows 10 Enterprise. This GPU took about 1 hour 4 minutes to probable prime (PRP) test with GeneferOCL4. Brent is a member of The Knights Who Say Ni! team.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz with 12GB RAM, running Windows 7 Professional. This computer took about 7 hours 10 minutes to complete the primality test using LLR.

For more details please see the official announcement.
29 Nov 2016 | 12:05:44 UTC · Comment


Another PPS Mega Prime!
On 27 November 2016, 04:28:15 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:
611*2^3334875+1

The prime is 1,003,901 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 193rd overall.

The discovery was made by John S. Chambers (Johnny Rotten) of the United States using an Intel(R) Core(TM) i7-5930K CPU @ 3.50GHz with 16GB RAM, running Microsoft Windows 7 Professional. This computer took about 45 minutes to complete the primality test using LLR. John is a member of the SETI.USA team.

The prime was verified on 27 November 2016 04:44:08 UTC, by John Murphy (TheDawgz) of the United States using an GenuineIntel Virtual CPU with 746MB RAM running Linux. This computer took about 53 minutes to complete the primality test using LLR. John is a member of the Aggie The Pew team.

For more details, please see the official announcement.
27 Nov 2016 | 17:30:42 UTC · Comment


GFN-262144 Mega Prime!
On 24 November 2016, 03:05:38 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

2042774^262144+1

The prime is 1,654,187 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 5th for Generalized Fermat primes and 47th overall.

The discovery was made by Tsuyoshi Ohsugi (motsu) of Japan using an NVIDIA GeForce GTX 750 Ti in an AMD Phenom(tm) II X6 1065T CPU with 12GB RAM, running Microsoft Windows 10 Professional. This GPU took about 1 hour 19 minutes to probable prime (PRP) test with GeneferOCL3. Tsuyoshi is a member of the Gridcoin team.

The prime was verified on 24 November 2016, 08:03:02 UTC by Michael Mamanakis (Michael Mamanakis) of the United States using an NVIDIA GeForce GTX 1080 in an Intel(R) Xeon(R) CPU E5-1603 @ 2.80GHz with 32GB RAM, running Microsoft Windows 7 Enterprise Edition. This GPU took about 25 minutes to probable prime (PRP) test with GeneferOCL4.

The PRP was confirmed prime by an Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz with 12GB RAM, running Windows 7 Professional. This computer took about 20 hours 36 minutes to complete the primality test using LLR.

For more information, please see the official announcement.
27 Nov 2016 | 17:02:06 UTC · Comment


Another PPS Mega Prime!
On 12 November 2016, 17:02:17 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

673*2^3330436+1

The prime is 1,002,564 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 193rd overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 CPU @ 3.50GHz with 8GB RAM, running Linux. This computer took about 1 hour 12 minutes to complete the primality test using LLR.

The prime was verified on 12 November 2016, 17:23:33 UTC by John S. Chambers (Johnny Rotten) of the United States using an Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz with 16GB RAM, running Microsoft Windows 7 Professional Edition. This computer took about 1 hour 23 minutes to complete the primality test using LLR. John is a member of the SETI.USA team.

For more details, please see the official announcement.
14 Nov 2016 | 12:56:38 UTC · Comment


World Record Colbert Number discovered!
On 31 October 2016, 22:13:54 UTC, PrimeGrid’s Seventeen or Bust subproject found the Mega Prime:

10223*2^31172165+1

The prime is 9,383,761 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 7th overall.

This is the largest prime found attempting to solve the Sierpinski Problem and eliminates k=10223 as a possible Sierpinski number. It is also the largest known Proth prime, the largest known Colbert number, and the largest prime PrimeGrid has discovered. Among the 10 largest known prime numbers, it is the only prime that is not a Mersenne number, and the only known non-Mersenne prime over 4 million digits.

Until the Seventeen or Bust project shut down earlier in the year, this search was a collaboration between PrimeGrid and Seventeen or Bust. This discovery would not have been possible without all the work done over the years by Seventeen or Bust.

The discovery was made by Szabolcs Peter (SyP) of Hungary using an Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz with 12GB RAM, running Windows 10 Enterprise Edition. This computer took about 8 days, 22 hours, 34 minutes to complete the primality test using LLR.

The prime was verified on 29 November 2016, 05:45:19 UTC by Heidi Kohne (Heidi1) of the United States using an AMD A6-3600 APU with 6GB RAM, running Microsoft Windows 7 Home Premium. This computer took about 27 days, 7 hours, 33 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
9 Nov 2016 | 16:57:51 UTC · Comment


Yes, its another PPS Mega Prime!
On 4 November 2016, 06:03:37 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

655*2^3327518+1

The prime is 1,001,686 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 196th overall.

The discovery was made by Paul Mazumdar (pm107) of the United Kingdom using an Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz with 16GB RAM, running Windows 10 Education Edition. This computer took about 1 hour 5 minutes to complete the primality test using LLR. Paul is a member of the University of Cambridge team.

The prime was verified on 4 November 2016, 14:34:01 UTC by Toshitaka Kumagai (Toshitaka Kumagai) of Japan using an Intel(R) Xeon(R) CPU E5-2643 @ 3.30GHz with 256GB RAM, running Windows 10 Core Edition. This computer took about 1 hour 22 Minutes to complete the primality test using LLR.

For more details, please see the official announcement.
5 Nov 2016 | 11:32:12 UTC · Comment


Another PPS Mega Prime!
On 3 November 2016, 17:52:13 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

659*2^3327371+1

The prime is 1,001,642 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 196th overall.

The discovery was made by Dejana Ristic (Dejana Ristic) of Germany using an Intel(R) Xeon(R) CPU E3-1245 v3 @ 3.40GHz with 8GB RAM, running Windows 7 Enterprise Edition. This computer took about 1 hour 1 minute to complete the primality test using LLR. Dejana is a member of the Rechenkraft.net team.

The prime was verified on 4 November 2016, 09:03:57 UTC by Steve King (steveking) of the United States using an Intel(R) Core(TM) i3-4010U CPU @ 1.70GHz with 12GB RAM, running Windows 10 Core Edition. This computer took about 4 hours to complete the primality test using LLR.

For more details, please see the official announcement.
5 Nov 2016 | 10:53:25 UTC · Comment


AP26 Found!
On 3 November 2016, 23:35:42 UTC, PrimeGrid’s AP27 Search (Arithmetic Progression of 27 primes) found the progression of 26 primes:

149836681069944461+7725290*23#*n for n=0..25

The discovery was made by Takeshi Nakamura (kurogane-t) of Japan using a NVIDIA GTX 1070 on an Intel(R) Xeon(R) E5-2667 v3 @ 3.20GHz with 16GB RAM, running Windows 10 Core x64 Edition. This computer took about 30 minutes to process the task (each task tests 100 progression differences of 10 shifts each). Takeshi is a member of the BOINC@MIXI team.

The progression was verified on 4 November 2016 03:37:51 UTC, by James Nobis (quel) of the United States using an AMD Tahiti GPU on an AMD Opteron(tm) 3648 CPU running Linux. This computer took about 1 hour 21 minutes to process the task. James is a member of the Sicituradastra. team.

The AP26 will be listed in Jens Kruse Andersen's Primes in Arithmetic Progression Records page under the section(s):

All known AP24 to AP26

For all APs found 23 and greater, please see PrimeGrid's AP26 Statistics.

For more details, please see the official announcement.
4 Nov 2016 | 17:03:59 UTC · Comment


PPS Mega Prime!
On 2 November 2016, 16:08:03 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

821*2^3327003+1

The prime is 1,001,531 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 196th overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 CPU @ 3.50GHz with 8GB RAM, running Linux. This computer took about 1 hour 1 minute to complete the primality test using LLR.

The prime was verified on 2 November 2016, 17:04:43 UTC by Chris Hoefliger ({CurlY BracketS}) of Switzerland using an Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 1 hour 55 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
3 Nov 2016 | 12:01:52 UTC · Comment


PSP Double Check
Since the demise of the original Prime Sierpinski Project (PSP) two years ago, PrimeGrid has been continuing its own work on PSP. The time has come to double check all of the PSP tasks done external to PrimeGrid. All of our own PSP tasks are already double checked.

The double check tasks are a lot smaller than the normal PSP tasks, but there's a lot of work to be done. If you have some spare computing power and would like to contribute, you may do so by selecting "Prime Sierpinski Project LLR (PSP)' on the PrimeGrid preferences page. This is a CPU-only project.

More details and discussion can be found in this thread: http://www.primegrid.com/forum_thread.php?id=7093
2 Nov 2016 | 14:22:57 UTC · Comment


Another PPS Mega Prime!
On 30 October 2016, 07:20:52 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

555*2^3325925+1

The prime is 1,001,206 digits long and will enter Chris Caldwell's “The Largest Known Primes Database” ranked 196th overall.

The discovery was made by Alexander Falk (Alexander Falk) of the United States using an Intel(R) Core(TM) i7-4690HQ CPU @ 2.60GHz with 16GB RAM, running Windows 10 Professional. This computer took about 4 hours 12 minutes to complete the primality test using LLR. Alexander is a member of The Knights Who Say Ni! team.

The prime was verified on 30 October 2016 16:18:08 UTC, by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 8GB RAM running Linux. This computer took about 1 hour 6 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
31 Oct 2016 | 17:13:17 UTC · Comment


PPS Mega Prime!
On 24 October 2016, 17:17:12 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

791*2^3323995+1

The prime is 1,000,626 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 197th overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 8GB RAM, running Linux. This computer took about 1 hour 8 minutes to complete the primality test using LLR.

The prime was verified on 26 October 2016 10:21:20 UTC, by Christoph Wolf ([CSF] Christoph Wolf) of Germany using an Intel(R) Core(TM) i7-4770K CPU @ 3.50GHz with 8GB RAM running Windows 10 Professional. This computer took about 1 hour 11 minutes to complete the primality test using LLR. Christoph is a member of the CRUNCHERS SANS FRONTIERES team.

For more details, please see the official announcement.
25 Oct 2016 | 12:23:16 UTC · Comment


New BOINC Sub-Project: GCW Sieve
We have opened Generalized Cullen Woodall sieve in BOINC to do new sieving work for the upcoming GCW move from PRPNet to BOINC in early 2017. The sieve for GCW was previously a manual effort. The sieve comes with an all new badge and user statistics.

We're searching for the first known Generalized Cullen prime in each of 14 bases. Once a Prime is found work on that Base will cease. Sieving makes the up and coming LLR work more efficient by removing candidates that have factors and so can't be Prime.

For more information, or to discuss the GCW Sieve, please see this forum thread.
22 Oct 2016 | 14:55:52 UTC · Comment


Another PPS Mega Prime!
On 21 October 2016, 18:12:50 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

597*2^3322871+1

The prime is 1,000,287 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 197th overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 8GB RAM, running Linux. This computer took about 1 hour 11 minutes to complete the primality test using LLR.

The prime was verified on 22 October 2016 00:51:34 UTC, by Lucas Brown (LucasBrown) of the United States using an Intel(R) Core(TM) i7-6700K CPU @ 4GHz with 64GB RAM running Linux. This computer took about 46 minutes to complete the primality test using LLR. Lucas is a member of the XKCD team.

For more details, please see the official announcement.
22 Oct 2016 | 9:12:21 UTC · Comment


Another GFN-131072 Mega Prime!
On 14 October 2016, 19:17:01 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

44085096^131072+1

The prime is 1,001,953 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 18th for Generalized Fermat primes and 193rd overall.

The discovery was made by Alejandro V. Mena (Alejandro V. Mena) of Mexico using an NVIDIA Tesla K40c in an Intel(R) Xeon(R) CPU E5-2620 v2 @ 2.10GHz with 56GB RAM, running Microsoft Windows 7 Professional. This GPU took about 18 minutes to probable prime (PRP) test with GeneferOCL4. Alejandro is a member of the MENA_COMP_DIE_FI_UNAM team.

The prime was verified on 15 October 2016, 10:27:16 UTC by Michael Mamanakis (Michael Mamanakis) of the United States using an NVIDIA GeForce GTX 1080 in an Intel(R) Xeon(R) CPU E5-1607 v2 @ 3.00GHz with 32GB RAM, running Microsoft Windows 10 Enterprise. This GPU took about 10 minutes to probable prime (PRP) test with GeneferOCL4.

The PRP was confirmed prime by an Intel(R) Core(TM) i5-4670K CPU @ 3.40GHz with 8GB RAM, running Windows 7 Professional. This computer took about 9 hours 14 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
15 Oct 2016 | 12:01:02 UTC · Comment


GFN-131072 Mega Prime!
On 5 October 2016, 19:10:08 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

44049878^131072+1

The prime is 1,001,908 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 18th for Generalized Fermat primes and 191st overall.

The discovery was made by Alexander Falk (Alexander Falk) of the United States using an NVIDIA GeForce GTX 970 in an Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 10 Professional. This GPU took about 14 minutes to probable prime (PRP) test with GeneferOCL4. Alexander is a member of The Knights Who Say Ni! team.

The PRP was confirmed prime by an Intel(R) Core(TM) i5-4670K CPU @ 3.40GHz with 8GB RAM, running Windows 7 Professional. This computer took about 9 hours 33 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
10 Oct 2016 | 10:40:18 UTC · Comment


PRPNet GCW Mega Prime!
On 8 October 2016, 21:01:14 UTC, PrimeGrid’s PRPNet found the largest known generalized Cullen prime:

682156*79^682156+1

The prime is 1,294,484 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for generalized Generalized Cullen and Generalized Cullen-Woodall primes and 83rd overall.

The discovery was made by Franz-Xaver Harvanek (XAVER) of Austria using an Intel(R) Core(TM) i7-5960X CPU @ 3.00GHz with 32GB RAM, running Microsoft Windows 7 Ultimate. This computer took 3 hours and 44 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
9 Oct 2016 | 21:55:11 UTC · Comment


Its another PPS Mega Prime!
On 8 October 2016, 05:09:38 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

415*2^3559614+1

The prime is 1,071,554 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 134th overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz with 8GB RAM, running Linux. This computer took about 1 hour 26 minutes to complete the primality test using LLR.

The prime was verified on 8 October 2016, 06:43:05 UTC by Alexander Falk (Alexander Falk) of the United States using an Intel(R) Xeon(TM) X5680 CPU @ 3.33GHz with 8GB RAM, running Linux. This computer took about 2 hours 57 minutes to complete the primality test using LLR. Alexander is a member of The Knights Who Say Ni! team.

For more details, please see the official announcement.
8 Oct 2016 | 18:04:14 UTC · Comment


Could it be? Yes, its another PPS Mega Prime!
On 30 September 2016, 09:27:42 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

465*2^3536871+1

The prime is 1,064,707 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 138th overall.

The discovery was made by Kenneth Biscop (Kenneth) of Belgium using an Intel(R) Core(TM) i5-4460 CPU @ 3.20GHz with 7GB RAM, running Windows 8.1. This computer took about 1 hour 33 minutes to complete the primality test using LLR. Kenneth is a member of the VUB/ULB team.

The prime was verified on 30 September 2016 09:30:54 UTC, by Els Floren (Kurt Janssens) of Belgium using an Intel(R) Core(TM) i5-4670 CPU @ 3.40GHz with 16GB RAM running Windows 8.1. This computer took about 1 hour 44 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
1 Oct 2016 | 17:10:48 UTC · Comment


TRP Sieve tasks to increase in size
We expect to increase the sieve of the TRP-Sieve tasks by a factor of five sometime after 18:00 on Monday, October 3rd.

More information and discussion can be found in this forum thread: http://www.primegrid.com/forum_thread.php?id=7040
30 Sep 2016 | 16:27:51 UTC · Comment


Another PPS Mega Prime!
On 28 September 2016, 12:23:48 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

447*2^3533656+1

The prime is 1,063,740 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 138th overall.

The discovery was made by Stefan Geiger (Steve) of Austria using an Intel(R) Core(TM) i7-6700K CPU @ 4GHz with 16GB RAM, running Windows 10. This computer took about 42 minutes to complete the primality test using LLR. Stefan is a member of the Aggie The Pew team.

The prime was verified on 29 September 2016 06:53:13 UTC, by Eric Eskam (Doc No) of the United States using an Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz with 8GB RAM running Windows 10. This computer took about 1 hour 21 minutes to complete the primality test using LLR. Eric is a member of the Heinlein Fans team.

For more details, please see the official announcement.
29 Sep 2016 | 10:51:07 UTC · Comment


The Hunt for AP27
PrimeGrid has begun searching for an AP27 (arithmetic progression of primes of 27 terms). Six years ago, we found the first known AP26. Help us search for an AP27!

Details and discussions can be found on the forums.
20 Sep 2016 | 17:39:19 UTC · Comment


World Record Twin Primes Found!
On 14 September 2016 04:24:46 UTC, PrimeGrid’s Sophie Germain Prime Search found World Record twin primes:

2996863034895*2^1290000±1

The twin primes are 388,342 digits long, eclipsing the previous record of 200,700 digits. They will enter Chris Caldwell's The Largest Known Primes Database ranked 1st for twins, and each entered individually ranked 4180th overall.

The discovery was made by Tom Greer (tng*) of the United States using an Intel(R) Xeon(R) CPU E5-2623 v3 @ 3GHz with 32 GB RAM running Windows 10 Professional. This computer, using LLR, took approximately 23 minutes to complete the primality tests of both primes. Tom is a member of the Sicituradastra. team.

The prime was verified on 15 September 2016 01:32:51 UTC, by Don Palmer (Don Palmer) of Canada using an Intel(R) Core(TM)2 Duo CPU E7600 @ 3.06GHz with 4 GB RAM running OS X 10.11.6. This computer, using LLR, took approximately 1 hour 37 minutes to complete the primality tests of both primes. Don is a member of the Team Canada team.

For more details, please see the official announcement.
20 Sep 2016 | 12:47:37 UTC · Comment


Double checking is now required for all tasks
PrimeGrid has turned on double checking for the SGS-LLR, PPSE-LLR, and PPS-LLR sub-projects. All of our other projects already had double checking enabled.

More details and discussion can be found here: http://www.primegrid.com/forum_thread.php?id=7007
12 Sep 2016 | 13:02:29 UTC · Comment


Another PPS Mega Prime!
On 5 September 2016, 02:15:19 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

495*2^3484656+1

The prime is 1,048,989 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 152nd overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 8GB RAM, running Linux. This computer took about 1 hour 8 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
8 Sep 2016 | 20:52:07 UTC · Comment


Yes, Its Another PPS Mega Prime!
On 29 August 2016, 10:26:22 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

491*2^3473837+1

The prime is 1,045,732 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 154th overall.

The discovery was made by Stephen Norton (spnorton) of the United States using an Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz with 16GB RAM, running Microsoft Windows 7 Professional x64 Edition. This computer took about 55 minutes to complete the primality test using LLR. Stephen is a member of the Alien Prime Cult team.

For more details, please see the official announcement.
7 Sep 2016 | 16:09:19 UTC · Comment


Another PPS Mega Prime!
On 23 August 2016, 01:58:59 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

453*2^3461688+1


The prime is 1,042,075 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 153rd overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 8GB RAM, running Linux. This computer took about 1 hour 11 minutes to complete the primality test using LLR.

The prime was verified on 23 August 2016, 11:32:10 UTC by Franz-Xaver Harvanek (XAVER) of Austria using an Intel(R) Core(TM) i7-5960X CPU @ 3.00GHz with 32GB RAM, running Microsoft Windows 7 Ultimate. This computer took about 1 hour 17 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
25 Aug 2016 | 14:51:54 UTC · Comment


SR5 Mega Prime!
On 20 August 2016, 16:21:09 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=180062 by finding the mega prime:

180062*5^2249192-1

The prime is 1,572,123 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 48th overall. This is the largest known base 5 mega prime. 74 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Stefan Larsson (288larsson) of Sweden using an Intel(R) Core(TM) i7-5775C CPU @ 3.30GHz with 8GB RAM running Linux. This computer took about 14 hours 3 minutes to complete the primality test using LLR. Stefan is a member of the Sicituradastra. team.

For more details, please see the official announcement.
25 Aug 2016 | 14:39:13 UTC · Comment


GFN-262144 Mega Prime!
On 10 August 2016, 19:21:20 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

1828858^262144+1

The prime is 1,641,593 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 5th for Generalized Fermat primes and 43rd overall.

The discovery was made by Brook Harste (brinktastee) of the United States using an NVIDIA GeForce GTX 980 Ti in an Intel(R) Core(TM) i7-3820 CPU @ 3.60GHz with 16GB RAM, running Microsoft Windows 10 Professional. This GPU took about 17 minutes to probable prime (PRP) test with GeneferOCL4. Brook is a member of the Aggie The Pew team.

The prime was verified on 10 August 2016, 21:06:33 UTC by Frank Matillek (boss) of Germany using an NVIDIA GeForce GTX 660 Ti in an Intel(R) Core(TM)2 Quad CPU Q9400@ 2.66GHz with 4GB RAM, running Microsoft Windows 10 Professional. This GPU took about 39 minutes to probable prime (PRP) test with GeneferOCL4. Frank is a member of the SETI.Germany team.

For more details, please see the official announcement.
16 Aug 2016 | 16:28:36 UTC · Comment


Yet Another PPS Mega Prime!
On 25 July 2016, 05:31:32 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

479*2^3411975+1

The prime is 1,027,110 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 156th overall.

The discovery was made by Matt Jurach (mattozan) of the United States using an Intel(R) Core(TM) i7-5820k CPU @ 3.30GHz with 16GB RAM, running Microsoft Windows 7 Enterprise. This computer took about 48 minutes to complete the primality test using LLR. Matt is a member of the Aggie The Pew team.

The prime was verified on 25 July 2016, 06:24:44 UTC by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz with 8GB RAM, running Linux. This computer took about 1 hour 21 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
16 Aug 2016 | 16:14:50 UTC · Comment


Oh My! Another PPS Mega Prime!
On 14 July 2016, 18:48:35 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

453*2^3387048+1

The prime is 1,019,606 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 165th overall.

The discovery was made by Andreas Mueller (Andreas) of Germany using an Intel(R) Xeon(R) CPU E5620 @ 2.40GHz with 16GB RAM, running Linux. This computer took about 3 hours 40 minutes to complete the primality test using LLR.

The prime was verified on 14 July 2016, 19:08:33 UTC, by Steve King (steveking) of the United States using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 20GB RAM, running Microsoft Windows 10 Professional. This computer took about 1 hour 20 minutes to complete the primality test using LLR.

For more details, please see the official announcement.

20 Jul 2016 | 2:33:47 UTC · Comment


You Guessed It...Another PPS Mega Prime!
On 25 June 2016, 09:58:06 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

403*2^3334410+1

The prime is 1,003,716 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 172nd overall.

The discovery was made by Roman Trunov (stream) of Russia using an Intel(R) Pentium(R) CPU G860 @ 3.00GHz with 6GB RAM, running Linux. This computer took about 2 hours 44 minutes to complete the primality test using LLR.

The prime was verified on 25 June 2016, 17:18:48 UTC, by Jens Riemann (gemini8) of Germany using an Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz with 8GB RAM, running Linux. This computer took about 3 hours 44 minutes to complete the primality test using LLR. Jens is a member of the Rechenkraft.net team.

For more details, please see the official announcement.

20 Jul 2016 | 2:14:51 UTC · Comment


And the PPS Mega Primes Keep on Rolling!
On 24 June 2016, 01:57:14 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

309*2^3577339+1

The prime is 1,076,889 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 119th overall.

The discovery was made by Russell Mathers (Russ) of the United Kingdom using an Intel(R) Core(TM) i7-5960X CPU @ 3.00GHz with 32GB RAM, running Microsoft Windows 10 Professional. This computer took about 1 hour 11 minutes to complete the primality test using LLR.

The prime was verified on 24 June 2016, 21:32:07 UTC, by Jakub Pavlis (JakuP) of the Czech Republic using an Intel(R) Core(TM) i3-2310M CPU @ 2.10GHz with 4GB RAM, running Microsoft Windows 10 Professional. This computer took about 2 hours 55 minutes to complete the primality test using LLR. Jakub is a member of the Czech National Team.

For more details, please see the official announcement.

20 Jul 2016 | 1:52:03 UTC · Comment


Another PPS Mega Prime!
On 22 June 2016, 00:53:21 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

345*2^3532957+1

The prime is 1,063,529 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 130th overall.

The discovery was made by William de Thomas (wdethomas) of Puerto Rico using an Intel(R) Xeon(R) CPU E5-2623 v3 @ 3.00GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 1 hour 21 minutes to complete the primality test using LLR. William is a member of the Puerto Rico Assisting Science.

For more details, please see the official announcement.

19 Jul 2016 | 3:43:36 UTC · Comment


Another PPS Mega Prime!
On 20 June 2016, 12:52:22 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

323*2^3482789+1

The prime is 1,048,427 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 143rd overall.

The discovery was made by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM) i5-2400S CPU @ 2.50GHz with 4GB RAM, running Microsoft Windows 10 Enterprise. This computer took about 2 hours 23 minutes to complete the primality test using LLR. Scott is a member of the Duke University.

For more details, please see the official announcement.
19 Jul 2016 | 3:25:36 UTC · Comment


Another PPS Mega Prime!
On 23 June 2016, 09:03:40 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

381*2^3563676+1

The prime is 1,072,776 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 125th overall.

The discovery was made by Milan Fňašek (RNDR. MF1) of the Czech Republic using an Intel(R) Core(TM) i5-3470 CPU @ 3.20GHz with 8GB RAM, running Microsoft Windows 7 Professional. This computer took about 1 hour 22 minutes to complete the primality test using LLR. Milan is a member of the Czech National Team.

The prime was verified on 23 June 2016, 21:44:24 UTC, by Walter Darimont (Walter Darimont) of Belgium using an Intel(R) CPU @ 2.66GHz with 4GB RAM, running Linux. This computer took about 4 hours 26 minutes to complete the primality test using LLR. Walter is a member of the Aggie The Pew team.

For more details, please see the official announcement.
15 Jul 2016 | 2:56:03 UTC · Comment


Another PPS Mega Prime!
On 22 June 2016, 12:49:45 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

351*2^3545752+1

The prime is 1,067,381 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 127th overall.

The discovery was made by Sylvanus A. Zimmerman (Van Zimmerman) of the United States using an Intel(R) Xeon(R) CPU E3-1225 v3 @ 3.20GHz with 2GB RAM, running FreeBSD 10.3. This computer took about 1 hour 27 minutes to complete the primality test using LLR. Sylvanus is a member of the Aggie The Pew team.

The prime was verified on 24 June 2016, 04:28:31 UTC, by user (13G) of the Czech Republic using an Intel(R) Core(TM) i5-2415M CPU @ 2.30GHz with 8GB RAM, running Darwin. This computer took about 2 hours 33 minutes to complete the primality test using LLR. 13G is a member of the Czech National Team.

For more details, please see the official announcement.
15 Jul 2016 | 2:33:19 UTC · Comment


PPS Mega Prime!
On 21 June 2016, 15:59:00 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

329*2^3518451+1

The prime is 1,059,162 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 132nd overall.

The discovery was made by Stefan Larsson (288larsson) of Sweden using an Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz with 16GB RAM, running Microsoft Windows 10. This computer took about 1 hour 20 minutes to complete the primality test using LLR. Stefan is a member of the Sicituradastra. team.

The prime was verified on 23 June 2016, 19:45:48 UTC, by Wiktor Jezioro (Wiktor) of Poland using an Intel(R) Xeon(R) CPU E5-2690 v2 @ 3.00GHz with 30GB RAM, running Linux. This computer took about 1 hour 57 minutes to complete the primality test using LLR. Wiktor is a member of the BOINC@Poland team.

For more details, please see the official announcement.

15 Jul 2016 | 2:10:38 UTC · Comment


ESP Sieve shutting down July 31st
The ESP-Sieve has reached its optimal sieving depth and will be shut down soon. If you're close to that next badge level, now is the time to get it. The actual date will be depend on when work runs out, but we will make sure there's work until at least the 31st.

More information and discussion can be found here: http://www.primegrid.com/forum_thread.php?id=6883
29 Jun 2016 | 15:01:35 UTC · Comment


Please upgrade your Nvidia drivers!
Recently, Nvidia released driver 368.22 which fixes the serious error introduced with their 364.xx driver. Please upgrade to 368.22 or later, unless you are running Windows XP or Windows Vista.

If you are running the 364.xx or 365.xx drivers, it is imperative that you upgrade to 368.22 or later. The 364.xx and 365.xx drivers can produce incorrect calculation results.

However, if you are running Windows XP or Windows Vista, these versions of Windows are no longer supported by Nvidia's drivers as of 368.22. If you're running XP or Vista, you must revert to an earlier version of the driver (363.xx or earlier).
10 Jun 2016 | 16:27:09 UTC · Comment


SR5 Mega Prime - PrimeGrid's 100th MEGA Prime Find!!!
On 30 May 2016, 18:15:42 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=53546 by finding the mega prime:

53546*5^2216664-1

The prime is 1,549,387 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 48th overall. This is the largest known base 5 mega prime. 75 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Tom Greer (tng*) of the United States using an Intel(R) Xeon(R) CPU E5-2620 0 @ 2.00GHz with 32GB RAM running Microsoft Windows 7 Professional. This computer took about 29 hours 24 minutes to complete the primality test using LLR. Tom is a member of the Sicituradastra. team.

The prime was verified on 2 June 2016, 01:20:10 UTC by John Parker (Mike Parker) of the United States using an Intel(R) Core(TM) i7-5820K CPU @ 3.30GHz with 16GB RAM running Microsoft Windows 10. This computer took about 80 hours 8 minutes to complete the primality test using LLR. John is a member of the SETI.USA team.

For more details, please see the official announcement.

5 Jun 2016 | 17:58:41 UTC · Comment


Another PPS Mega Prime!
On 16 May 2016, 07:12:37 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

373*2^3404702+1

The prime is 1,024,921 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 152nd overall.

The discovery was made by Seonghwan Kim (ext2097) of South Korea using an Intel(R) Xeon(R) CPU E3-1231 v3 @ 3.40GHz with 4GB RAM, running Linux. This computer took about 56 minutes to complete the primality test using LLR. Seonghwan is a member of the SETIKAH@KOREA team.

The prime was verified on 17 May 2016, 01:25:38 UTC, by Bob Bussard (RGB) of Canada using an Intel(R) Core(TM) i5-3230M CPU @ 2.60GHz with 8GB RAM, running Microsoft Windows 8.1. This computer took about 3 hours 39 minutes to complete the primality test using LLR.

For more details, please see the official announcement.

22 May 2016 | 18:13:46 UTC · Comment


Another PPS Mega Prime!
On 9 May 2016, 13:07:05 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

303*2^3391977+1

The prime is 1,021,090 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 154th overall.

The discovery was made by Andreas Mueller (Andreas) of Germany using an Intel(R) Pentium(R) CPU G2130 @ 3.20GHz with 8GB RAM, running Microsoft Windows 7 Enterprise. This computer took about 2 hours 28 minutes to complete the primality test using LLR.

The prime was verified on 12 May 2016, 16:24:32 UTC, by Stephane Guichard (stef71000) of France using an Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz with 16GB RAM, running Microsoft Windows 10 Professional. This computer took about 2 hours 31 minutes to complete the primality test using LLR. Stephane is a member of the L'Alliance Francophone team.

For more details, please see the official announcement.

22 May 2016 | 17:55:40 UTC · Comment


GFN-262144 Mega Prime May Edition!
On 4 May 2016, 10:57:07 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

1615588^262144+1

The prime is 1,627,477 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 5th for Generalized Fermat primes and 44th overall.

The discovery was made by Brook Harste (brinktastee) of the United States using an NVIDIA GeForce GTX 980 Ti in an Intel(R) Core(TM) i7-3820 CPU @ 3.60GHz with 16GB RAM, running Microsoft Windows 10 Professional. This GPU took about 17 minutes to probable prime (PRP) test with GeneferOCL4. Brook is a member of the Aggie The Pew team.

The prime was verified on 8 May 2016, 15:28:12 UTC by Róbert Borbély (SosRud) of Hungary using an AMD Cypress in an Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 10 Professional. This GPU took about 1 hour and 36 minutes to probable prime (PRP) test with GeneferOCL4.

For more details, please see the official announcement.

9 May 2016 | 16:07:05 UTC · Comment


PPS Mega Prime!
On 10 April 2016, 19:53:20 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

369*2^3365614+1

The prime is 1,013,154 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 155th overall.

The discovery was made by Will Steinbach (bill1024) of the United States using an Intel(R) Xeon(R) CPU E5-2670 0 @ 2.60GHz with 32GB RAM, running Linux. This computer took about 1 hour 36 minutes to complete the primality test using LLR. Will is a member of the Crunching@EVGA team.

The prime was verified on 10 April 2016, 20:58:16 UTC, by Stephen Norton (spnorton) of the United States using an Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz with 32GB RAM, running Microsoft Windows 7 Professional. This computer took about 2 hour 52 minutes to complete the primality test using LLR. Stephen is a member of the Alien Prime Cult team.

For more details, please see the official announcement.
9 May 2016 | 14:52:19 UTC · Comment


Trouble with Nvidia's 364.xx driver
Numerous participants have had tasks fail due the Nvidia's buggy 364.xx driver. If you're using this driver, I recommend reverting to an earlier version of the driver with a major version number lower than 364.

If you're currently running an older version of the driver, I strongly recommend that you do not "upgrade" to 364.xx. I've also heard reports of this driver "bricking" GPUs, and that goes way, way beyond merely having some BOINC tasks fail.
16 Apr 2016 | 19:38:06 UTC · Comment


SR5 Mega Prime - March 2016 Edition Version 3.0
On 25 March 2016, 10:34:36 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=296024 by finding the mega prime:

296024*5^2185270-1

The prime is 1,527,444 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 50th overall. This is the largest known base 5 mega prime. 76 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Steven Wong (mackerel) of the United Kingdom using an Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz with 16GB RAM running Microsoft Windows 10. This computer took about 15 hours 10 minutes to complete the primality test using LLR. Steven is a member of the Aggie The Pew team.

The prime was verified on 29 March 2016, 09:01:18 UTC by Matthew Borneman (Maxwell [MM]) of the United States using an Intel(R) Core(TM)2 Duo CPU E7500 @ 2.93GHz with 4GB RAM running Microsoft Windows 7 Professional. This computer took about 65 hours 5 minutes to complete the primality test using LLR. Matthew is a member of the SETI.USA team.

For more details, please see the official announcement.

15 Apr 2016 | 19:24:37 UTC · Comment


Cullen Birthday Challenge starts April 19th 2016, 18:00:00 UTC
To celebrate the 149th birthday of James Cullen, the namesake of the Cullen primes we're looking for at PrimeGrid, we are hosting a 9 day challenge. This challenge starts on April 19th 18:00 UTC, his birthday.

For more information, questions and general banter and merry making please join us on the forums
9 Apr 2016 | 15:34:41 UTC · Comment


GFN-262144 Mega Prime March Edition!
On 5 March 2016, 18:56:52 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

1488256^262144+1

The prime is 1,618,131 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 5th for Generalized Fermat primes and 43rd overall.

The discovery was made by Stefan Larsson (288larsson) of Sweden using an AMD Hawaii in an Intel(R) Core(TM) i5-4670K CPU @ 3.40GHz with 8GB RAM, running Linux. This GPU took about 27 minutes to probable prime (PRP) test with GeneferOCL4. Stefan is a member of the Sicituradastra. team.

The prime was verified on 5 March 2016, 19:25:40 UTC by Dirk Kraemer (DoctorNow) of Germany using an NVIDIA GeForce GTX 760 in an AMD Phenom(tm) II X6 1045T Processor with 12GB RAM, running Windows Vista Home Premium. This GPU took about 1 hour and 5 minutes to probable prime (PRP) test with GeneferOCL3. Dirk is a member of the BOINC Confederation team.

For more details, please see the official announcement.

30 Mar 2016 | 4:03:43 UTC · Comment


PPS Mega Prime!
On 24 March 2016, 00:45:48 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

393*2^3349525+1

The prime is 1,008,311 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 153rd overall.

The discovery was made by Timothy Reichard (Timothy Reichard) of the United States using an Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz with 16GB RAM, running Darwin. This computer took about 1 hour 10 minutes to complete the primality test using LLR.

The prime was verified on 24 March 2016, 00:58:33 UTC, by Alex Huetter (ahlx) of Austria using an Intel(R) Core(TM) i5-5200U CPU @ 2.20GHz with 4GB RAM, running Microsoft Windows 10 Professional. This computer took about 1 hour 14 minutes to complete the primality test using LLR. Alex is a member of the Gentoo Linux Users Everywhere team.

For more details, please see the official announcement.

30 Mar 2016 | 3:30:27 UTC · Comment


SR5 Mega Prime - March 2016 Edition Version 2.0
On 15 March 2016, 18:24:24 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=92158 by finding the mega prime:

92158*5^2145024+1

The prime is 1,499,313 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 53rd overall. This is the largest known base 5 mega prime. 33 k's now remain in the Sierpinski Base 5 Problem.

The discovery was made by Karl Burridge (Aus_Karlos) of Australia using an Intel(R) Core(TM) i7 CPU 950 @ 3.07GHz with 8GB RAM running Linux. This computer took about 43 hours 17 minutes to complete the primality test using LLR.

For more details, please see the official announcement.

30 Mar 2016 | 2:34:56 UTC · Comment


SR5 Mega Prime - March 2016 Edition
On 6 March 2016, 07:54:42 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=77072 by finding the mega prime:

77072*5^2139921+1

The prime is 1,495,746 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 53rd overall. This is the largest known base 5 mega prime. 34 k's now remain in the Sierpinski Base 5 Problem.

The discovery was made by Wolfgang Becker (flex) of Germany using an Intel(R) Core(TM)2 Duo CPU E8500 @ 3.16GHz with 4GB RAM running Windows 10 Professional. This computer took about 10 hours 42 minutes to complete the primality test using LLR. Wolfgang is a member of the BOINC@Heidelberg team.

The prime was verified on 9 March 2016, 22:19:31 UTC by Magnus Karlsteen (pep) of Sweden using an Intel(R) Xeon(R) CPU X5690 @ 3.47GHz with 24GB RAM running Windows 7 Professional. This computer took about 9 hours 9 minutes to complete the primality test using LLR.


For more details, please see the official announcement.

30 Mar 2016 | 2:19:17 UTC · Comment


World Record Sophie Germain Prime!
On 29 February 2016 05:39:14 UTC, PrimeGrid’s Sophie Germain Prime Search found a World Record Sophie Germain prime: 2618163402417*2^1290000-1 (2p+1: 2618163402417*2^1290001-1)

The prime is 388,342 digits long, eclipsing the previous record of 200,701 digits. It enters Chris Caldwell's “The Largest Known Primes Database” ranked 1st for Sophie Germain primes and 3,747th overall.

The discovery was made by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM)2 Quad CPU Q6700 @ 2.66GHz with 4 GB RAM running Microsoft Windows 7 Enterprise. This computer, using LLR, took about 1 hour and 33 minutes to complete the primality test. Scott is a member of the Duke University team.

The prime was verified on 29 February 2016 06:21:47 UTC, by Vaughan Davies (vaughan) of Australia using an Intel(R) Core(TM) i7-4770S CPU @ 3.10GHz with 32 GB RAM running Microsoft Windows 7 Ultimate. This computer, using LLR, took about 47 minutes to complete the primality test. Vaughan is a member of the AMD Users team.

For more details, please see the official announcement.

6 Mar 2016 | 14:50:22 UTC · Comment


GeneferCUDA apps to be shut down permanently
When the upcoming GeneferOCL v3.3.0 apps are live, we will be permanently shutting down the GeneferCUDA apps.

More details are available in the Deprecating GeneferCUDA thread.

If there's a reason why you want to keep running GeneferCUDA, now is the time to speak up. Once we shut off GeneferCUDA it will be too late.
2 Mar 2016 | 17:02:55 UTC · Comment


LLR 3.8.17 is now live on all LLR projects
As of a short time ago, all LLR apps have been upgraded to BOINC version 7.06, which uses LLR 3.8.17.

If you're not using app_info (aka "anonymous platform"), or don't know what that means, no action is necessary on your part. BOINC will do the update automatically.

If you are using app_info in order to run LLR 3.8.17, it's no longer necessary to use app_info and you may, if you wish, switch back to using the stock apps.

If you are using app_info but are using an older version of LLR, you should update to the new version of LLR.

For more information please see the LLR 3.8.17 Testing thread.
2 Mar 2016 | 16:49:35 UTC · Comment


Another GFN-131072 Mega Prime!
On 25 February 2016, 02:26:37 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

43165206^131072+1

The prime is 1,000,753 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 15th for Generalized Fermat primes and 154th overall.

The discovery was made by Alen Kecic (Freezing) of Germany using an NVIDIA GeForce GTX 660 Ti in an Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz with 8GB RAM, running Windows 7 Professional. This GPU took 52 minutes to probable prime (PRP) test with GeneferOCL2. Alen is a member of the SETI.Germany team.

The prime was verified on 26 February 2016, 02:40:45 UTC by [CSF] Joris Degraide of France using an NVIDIA GeForce GTX 970M in an Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz with 16GB RAM, running Windows 7 Ultimate. This GPU took 48 minutes to probable prime (PRP) test with GeneferOCL2. [CSF] Joris Degraide is a member of the CRUNCHERS SANS FRONTIERES team.

For more details, please see the official announcement.

28 Feb 2016 | 20:42:12 UTC · Comment


GFN-131072 Mega Prime!
On 24 February 2016, 20:53:55 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

43163894^131072+1

The prime is 1,000,751 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 16th for Generalized Fermat primes and 154th overall.

The discovery was made by David E. Miller (dem0707) of the United States using an NVIDIA GeForce GTX 980 in an Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz with 16GB RAM, running Windows 7 Professional. This GPU took about 26 minutes to probable prime (PRP) test with GeneferOCL2. David is a member of the Crunching@EVGA team.

The prime was verified on 24 February 2016, 21:37:52 UTC by Alen Kecic (Freezing) of Germany using an NVIDIA GeForce GTX 660 Ti in an Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz with 8GB RAM, running Windows 7 Professional. This GPU took 48 minutes to probable prime (PRP) test with GeneferOCL2. Alen is a member of the SETI.Germany team.

For more details, please see the official announcement.

28 Feb 2016 | 20:10:45 UTC · Comment


Another PPS Mega Prime!
On 24 February 2016, 12:04:12 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

189*2^3596375+1

The prime is 1,082,620 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 106th overall.

The discovery was made by Hiroyuki Okazaki (zunewantan) of Japan using an Intel(R) Xeon(R) CPU E5-1630 v3 @ 3.70GHz with 16GB RAM, running Microsoft Windows 7 Professional. This computer took about 58 minutes to complete the primality test using LLR. Hiroyuki is a member of the Aggie The Pew team.

The prime was verified on 24 February 2016, 13:18:01 UTC, by user Shaman of the Czech Republic using an Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz with 8GB RAM, running Microsoft Windows 7 Professional. This computer took about 2 hours 2 minutes to complete the primality test using LLR. Shaman is a member of the Czech National Team team.

For more details, please see the official announcement.

26 Feb 2016 | 23:19:38 UTC · Comment


PPS Mega Prime!
On 21 February 2016, 16:55:42 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

387*2^3322763+1

The prime is 1,000,254 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 152nd overall.

The discovery was made by Sami Heikkilä (samuel7) of Finland using an Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz with 16GB RAM, running Microsoft Windows 10. This computer took about 1 hour 6 minutes to complete the primality test using LLR. Sami is a member of the PrimeSearchTeam team.

The prime was verified on 24 February 2016, 15:14:59 UTC, by William Donovan (Williamd007) of the United States using an AMD FX(tm)-9590 Eight-Core Processor with 16GB RAM, running Microsoft Windows 10. This computer took about 2 hours 27 minutes to complete the primality test using LLR. William is a member of the The Knights Who Say Ni! team.

For more details, please see the official announcement.

26 Feb 2016 | 22:31:10 UTC · Comment


GFN-262144 Mega Prime!
On 16 February 2016, 16:45:20 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

1415198^262144+1

The prime is 1,612,400 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 5th for Generalized Fermat primes and 43rd overall.

The discovery was made by Frank Matillek (boss) of Germany using an NVIDIA GeForce GTX 660 Ti in an Intel(R) Core(TM)2 Quad CPU Q9400 @ 2.66GHz with 4GB RAM, running Windows 7 Ultimate. This GPU took about 53 minutes to probable prime (PRP) test with GeneferOCL3. Frank is a member of the SETI.Germany team.

The prime was verified on 16 February 2016, 17:01:20 UTC by Alan Kong (Wingless Wonder) of the United States using an NVIDIA GeForce GTX Titan Black in an Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz with 32GB RAM, running Windows 10 Professional. This GPU took 30 minutes to probable prime (PRP) test with GeneferOCL3. Alan is a member of the AMD Users team.

For more details, please see the official announcement.

24 Feb 2016 | 18:56:05 UTC · Comment


PPS Mega Prime!
On 9 February 2016, 02:47:35 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

275*2^3585539+1

The prime is 1,079,358 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 104th overall.

The discovery was made by Tyler Bredl (1998golfer) of the United States using an Intel(R) Xeon(R) CPU E5-2666 v3 @ 2.90GHz with 60GB RAM, running Linux. This computer took about 3 hour 3 minutes to complete the primality test using LLR. Tyler is a member of the Aggie The Pew team.

The prime was verified on 9 February 2016, 22:55:34 UTC, by Andreas Mueller (Andreas) of Germany using an Intel(R) Xeon(R) CPU E5620 @ 2.40GHz with 16GB RAM, running Linux. This computer took about 3 hours 51 minutes to complete the primality test using LLR.

For more details, please see the official announcement.

17 Feb 2016 | 2:14:46 UTC · Comment


PPS Mega Prime!
On 25 January 2016, 11:24:35 UTC, PrimeGrid’s PPS Mega Prime Search project found the Mega Prime:

251*2^3574535+1

The prime is 1,076,045 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 105th overall.

The discovery was made by Randall Scalise (Randall J. Scalise) of the United States using an Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz with 8GB RAM, running Linux. This computer took about 1 hour 42 minutes to complete the primality test using LLR.

The prime was verified on 25 January 2016, 23:32:54 UTC, by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz with 8GB RAM, running Microsoft Windows 7 Enterprise. This computer took about 59 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

For more details, please see the official announcement.
1 Feb 2016 | 2:15:14 UTC · Comment


SR5 Mega Prime - January 2016 Edition
On 11 January 2016, 10:02:08 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=306398 by finding the mega prime:

306398*5^2112410-1

The prime is 1,476,517 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 50th overall. This is the largest known base 5 mega prime. 77 k's now remain in the Riesel Base 5 Problem.

The discovery was made by André Ahlfors Dahl (NocFlame) of Sweden using an Intel(R) Xeon(R) CPU W3520 @ 2.67GHz with 16GB RAM running Linux. This computer took about 77 hours 10 minutes to complete the primality test using LLR. André is a member of the Gridcoin team.

The prime was verified on 17 January 2016, 19:36:26 UTC by evaotaku00 of the United States using an Intel(R) Xeon(R) CPU X5355 @ 2.66GHz with 24GB RAM running Darwin. This computer took about 77 hours 10 minutes to complete the primality test using LLR. evaotaku00 is a member of the Ars Technica team.

For more details, please see the official announcement.
1 Feb 2016 | 2:05:49 UTC · Comment


SR5 Mega Prime - November 2015 Edition
On 10 November 2015, 07:16:15 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=154222 by finding the mega prime:

154222*5^2091432+1

The prime is 1,461,854 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 51st overall. This is the largest known base 5 mega prime. 35 k's now remain in the Sierpinski Base 5 Problem.

The discovery was made by Scott Brown (Scott Brown) of the United States using an Intel(R) Xeon(R) CPU E5-1620 v3 @ 3.50GHz with 16GB RAM running Windows 10 Professional. This computer took about 5 hours and 5 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.


For more details, please see the official announcement.
1 Feb 2016 | 1:54:19 UTC · Comment


Tour de Primes 2016
In less than 24 hours, it will be February -- and that means it's time for the 2016 Tour de Primes Challenge!

Unlike other challenges, there's no trophy for participation. This challenge is all about finding prime numbers.

For 2016, we've added a new trophy -- the red jersey -- which will be awarded to whomever finds the largest prime number during the month of February.

And, of course, we'll be awarding the green, yellow, and polk-a-dot jerseys as in previous years.

For more information, please see Tour de Primes 2016.

Good luck everyone!
31 Jan 2016 | 15:29:24 UTC · Comment


GFN=15 (32768) Switching to OCL2 soon (DONE)
:::::::::: EDIT: GFN15 has been switched to OCL2. ::::::::::


In about a week, GFN 15 (32768) will switch from OCL3 to OCL2.

IMPORTANT: Some GPUs can not run OCL2!!!

Older Nvidia GPUs that are below CC 2.0 will not work.

ATI/AMD GPUs, on Mac only, will not work.

For more details and discussion, please see this thread.
4 Dec 2015 | 14:18:36 UTC · Comment


GFN-131072 Mega Prime!
On 9 Nov 2015, 18:02:51 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:

42654182^131072+1

The prime is 1,000,075 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 14th for Generalized Fermat primes and 143rd overall. Of note, this find appears to be the first Titanic prime (>= 1000 digits) found using fixed-point numbers.

The discovery was made by Andrew M. Farrow (Nortech) of Australia using an NVIDIA GeForce GTX 960 in an Intel(R) Core(TM) i3-4170 CPU @ 3.70GHz with 4GB RAM running Linux. This GPU took about 1 hour 2 minutes to probable prime (PRP) test with GeneferOCL2.

The prime was verified by Patrick Schöfer (pschoefer) of Germany using an NVIDIA GeForce GTX 660 Ti in an Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz with 16GB RAM running Windows 7 Professional. This computer took about 47 minutes to probable prime (PRP) test with GeneferOCL2. Patrick is a member of the SETI.Germany team.

For more details, please see the official announcement.
11 Nov 2015 | 2:56:03 UTC · Comment


New LLR app (7.05) released
A new app (7.05) has been released for all LLR projects. LLR itself is the same, but the wrapper's trickle logic is improved.

The discussion thread is here.
5 Nov 2015 | 2:30:18 UTC · Comment


PPS Mega Prime!
On 30 October 2015, 03:27:00 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

191*2^3548117+1

The prime is 1,068,092 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 105th overall.

The discovery was made by Roman Azarenko (Roman Azarenko) of Russia using an Intel(R) Xeon(R) CPU E3-1240 v3 @ 3.40GHz with 2GB RAM, running Linux. This computer took about 1 hour 7 minutes to complete the primality test using LLR. Roman is a member of the Russia Team.

The prime was verified on 2 November 2015, 22:02:26 UTC, by Jon Beard (Fuzzy Duck) of Vietnam using an Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz with 32GB RAM, running Microsoft Windows 10. This computer took about 7 hours 1 minute to complete the primality test using LLR. Jon is a member of the The Knights Who Say Ni! team.

For more details, please see the official announcement.

5 Nov 2015 | 2:14:10 UTC · Comment


GFN 262144, GFN 524288, and GFN 1048576 Now Open!
The last three GFN ranges have been reopened on the BOINC server, and the corresponding GFN 262144 and GFN 524288 PRPNet ports have been shut down.

Details and discussion can be found in this thread.
4 Nov 2015 | 23:03:55 UTC · Comment


Genefer 3.2.9 released for n=4194304 and n=2097152
I have put Genefer 3.2.9 into production on the n=21 and n=22 (World Record) projects. (3.2.9 was already running on n=15, n=16, and n=17.)

This may affect you in the following ways:


  • If you use app_info, you should update your configuration to use the new 3.2.9 apps if you're not already doing so. (If you're not using app_info, or don't know what app_info is, no action is necessary on your part.)
  • N=21 and N=22 (WR) will now use trickles to extend deadlines.
  • Because the deadline extension mechanism is now functional on n=21, the deadline has been lowered back to 21 days. The max deadline is unchanged at 84 days, so effectively you now have twice as much time to complete the task while abandoned tasks will be resent in half the time.


Discussion about this release is in this thread. 4 Nov 2015 | 5:31:35 UTC · Comment


SR5 Mega Prime!
On 21 October 2015, 05:23:34 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=100186 by finding the mega prime:

100186*5^2079747-1

The prime is 1,453,686 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 53rd overall. This is the largest known base 5 mega prime. 78 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Toshitaka Kumagai (Toshitaka Kumagai) of Japan using an Intel(R) Xeon(R) CPU E3-1220 V2 @ 3.10GHz with 32GB RAM running Linux. This computer took about 15 hours 41 minutes to complete the primality test using LLR.

The prime was verified on 21 October 2015, 18:46:14 UTC by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz with 8GB RAM running Microsoft Windows 7 Enterprise. This computer took about 27 hours 36 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

For more details, please see the official announcement.

26 Oct 2015 | 1:33:48 UTC · Comment


GFN 131072 (Low) and GFN 131072 (Mega)
We have opened up the n=17 (131072) GFN range on BOINC -- not just once, but twice!

In addition to the normal 131072 (aka "Low") range, we've also opened up a second 131072 range starting at a very high b -- just high enough so the numbers are at least a million digits long. Since these are crunchable with the new OCL2 GPU app, this makes it one of the fastest mega-prime searches available.

For discussion or more information, please click here.
16 Oct 2015 | 22:02:18 UTC · Comment


GFN 32768 and GFN 65536 now available on BOINC
Generalized Fermat Number (GFN) tests with n=32768 and n=65536 are now available on BOINC by selecting the appropriate tasks under "PrimeGrid Preferences".

Both CPU and GPU tasks are available. Initially, we're double checking earlier work that was only single checked.

More details can be found here.
13 Oct 2015 | 20:35:22 UTC · Comment


GFN-Short is... not so short anymore
The GFN-Short project has completed its double-checking diversion and has moved on to its next and permanent n-range: n=21 (2097152)

These tasks are HUGE. Not quite as large as the world record tasks, but still very large. Calling them "Short" would make even an advertising executive blush. So "Short" is out. This is now the "GFN-21" project.

Expect run times to be about 15-20 hours for a fairly fast GPU (and just under 10 for the very fastest). Expect about 75 hours for FMA3 capable Haswell CPUs, and about 130 hours for fast modern CPUs without AVX (which unfortunately includes all AMD CPUs, since their AVX instruction set is almost useless.)

Time estimates are based on a single task running, so expect somewhat longer times if you're loading up all the cores. And, as always, your mileage may vary.

Also, expect run times to grow relatively quickly as 'b' grows in magnitude.

The deadline for these tasks is currently a whopping 42 days -- much longer than the times mentioned above for relatively modern computers. Slow computers, old computers, part time crunchers, and so on should still be able to meet the deadline. Once we release the "deadline extension" version of the Genefer app we'll lower the deadline which will give us a faster turnaround for abandoned tasks.

At the current time, this temporarily leaves us without any true short GFN tasks on the BOINC server, but we will be opening up additional n-ranges in the near future with a wide range of much shorter tasks.

Happy crunching!

(All things GFN can be discussed here: http://www.primegrid.com/forum_forum.php?id=75)
15 Sep 2015 | 19:25:08 UTC · Comment


PPS Mega Prime - September Edition!
On 1 September 2015, 05:57:32 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

141*2^3529287+1

The prime is 1,062,424 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 108th overall.

The discovery was made by Chris Hoefliger ({CurlY BracketS}) of Switzerland using an Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows Professional 8.1. This computer took about 3 hours 9 minutes to complete the primality test using LLR.

The prime was verified on 1 September 2015, 08:36:00 UTC, by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz with 8GB RAM, running Microsoft Windows 7 Enterprise. This computer took about 1 hour and 14 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

For more details, please see the official announcement.
8 Sep 2015 | 0:58:46 UTC · Comment


New LLR apps and deadline extensions
All LLR projects (SGS, CUL, WOO, PPS, PPSE, PPS-MEGA, 321, SoB, PSP, ESP, TRP, SR5) have been upgraded to version 7.03.

If you're using app_info, aka anonymous platform, you'll definitely want to upgrade your apps to get the latest wrapper AND llr executables. The llr.ini file is unchanged.

The new wrapper does trickle-ups to facilitate automatic deadline extensions if your computer is running late. Please see this thread for details.

The new LLR version fixes some error handling and resolves a problem where tests near FFT boundaries might run much slower than expected. LLr 3.8.16 is discussed in this thread.

Please let us know if there's any problems in this thread.
28 Aug 2015 | 12:37:15 UTC · Comment


PPS Mega Prime!
On 2 August 2015, 07:43:42 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

135*2^3518338+1

The prime is 1,059,128 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 107th overall.

The discovery was made by Evelyn Chew (Crackenback) of Australia using an Intel(R) Xeon(R) CPU E5-2603 0 @ 1.80GHz with 8GB RAM, running Microsoft Windows Server 2008. This computer took about 2 hours 57 minutes to complete the primality test using LLR. Evelyn is a member of the BOINC@AUSTRALIA team.

The prime was verified on 2 August 2015, 09:09:01 UTC, by Paulo Silva (Cyph3r) of Portugal using an Intel(R) Xeon(R) CPU E5-2670 0 @ 2.60GHz with 60GB RAM, running Linux. This computer took about 3 hour and 25 minutes to complete the primality test using LLR. Paulo is a member of the Portugal@Home team.

For more details, please see the official announcement.
19 Aug 2015 | 2:07:25 UTC · Comment


321 Mega Prime! (2015 Edition, part 2)
On 23 June 2015 20:49:21 UTC, PrimeGrid’s 321 Prime Search project found the mega prime:

3*2^11895718-1

The prime is 3,580,969 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 12th overall. This is the largest known 321 mega prime and the largest prime found to date at PrimeGrid!

The discovery was made by Michael Schulz (Michael Schulz) of Germany using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 16 GB RAM running Darwin 14.3.0. This computer took about 9 hours and 57 minutes to complete the primality test using LLR.

The prime was verified on 27 June 2015 3:56:03 UTC, by user Matthew of New Zealand using an Intel(R) Core(TM) i7-4510U CPU @ 2.00GHz with 8 GB RAM running Windows 7 Professional. This computer took about 33 hours and 40 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
12 Jul 2015 | 19:31:33 UTC · Comment


SR5 Mega Prime!
On 23 May 2015, 17:47:52 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=144052 by finding the mega prime:

144052*5^2018290+1

The prime is 1,410,730 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 54th overall. This is the largest known base 5 mega prime. 36 k's now remain in the Sierpinski Base 5 Problem.

The discovery was made by Wolfgang Schmidt (Artist) of Germany using an Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz with 16GB RAM running Linux. This computer took about 6 hours and 17 minutes to complete the primality test using LLR. Wolfgang is a member of the Special: Off-Topic team.

The prime was verified on 26 May 2015, 17:48:33 UTC, by user RoBorg of the United Kingdom using an Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz with 8GB RAM running Microsoft Windows 7 Professional. This computer took about 15 hours and 24 minutes to complete the primality test using LLR. RoBorg is a member of the Brony@Home team.

For more details, please see the official announcement.
29 Jun 2015 | 2:29:43 UTC · Comment


Another PPS Mega Prime!
On 10 May 2015, 02:13:21 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

195*2^3486379+1

The prime is 1,049,507 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 109th overall.

The discovery was made by Naoki Yoshioka (oevrtaker@biomaterial) of Japan using an Intel(R) Xeon(R) CPU E5-2687W 0 @ 3.10GHz with 64GB RAM running Microsoft Windows 8.1 Enterprise. This computer took about 1 hour and 32 minutes to complete the primality test using LLR. Naoki is a member of the Doshisha University team.

The prime was verified on 10 May 2015, 10:12:42 UTC, by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz with 8GB RAM, running Microsoft Windows 7 Enterprise. This computer took about 1 hour and 14 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

For more details, please see the official announcement.
24 Jun 2015 | 2:58:30 UTC · Comment


Putting the "Short" back in GFN-Short
The GFN-Short project has just about reached the end of the n=20 range of GFN tasks and is transitioning to n=17 tasks. The n=17 tasks are about 60 times shorter than n=20.

It will take a couple of months for all of the older n=20 work units to complete, so even after the n=17 tasks start going out it will still be possible to get the occasional n=20 task.

The new n=17 tasks will have a 4 day deadline.

For more details and discussion, please see this forum thread.

16 Jun 2015 | 13:32:40 UTC · Comment


PPS Mega Prime!
On 10 May 2015, 00:56:17 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

249*2^3486411+1

The prime is 1,049,517 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 109th overall.

The discovery was made by Evelyn Chew (Crackenback) of Australia using an Intel(R) Pentium(R) CPU G3220 @ 3.00GHz with 4GB RAM running Microsoft Windows 7 Enterprise. This computer took about 2 hours 37 minutes to complete the primality test using LLR. Evelyn is a member of the BOINC@AUSTRALIA team.

The prime was verified on 10 May 2015, 09:36:32 UTC, by Naoki Yoshioka (oevrtaker@biomaterial) of Japan using an Intel(R) Xeon(R) CPU E5-2687W 0 @ 3.10GHz with 64GB RAM running Microsoft Windows 8.1 Enterprise. This computer took about 1 hour and 32 minutes to complete the primality test using LLR. Naoki is a member of the Doshisha University team.

For more details, please see the official announcement.
16 Jun 2015 | 13:23:41 UTC · Comment


PPS Mega Prime!
On 19 April 2015, 01:16:36 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

197*2^3477399+1

The prime is 1,046,804 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 109th overall.

The discovery was made by Tom Greer (tng*) of the United States using an Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz with 16GB RAM running Microsoft Windows 7 Ultimate. This computer took about 3 hours 5 minutes to complete the primality test using LLR. Tom is a member of the Sicituradastra. team.

The prime was verified on 19 April 2015, 03:32:00 UTC, by Naoki Yoshioka (oevrtaker@biomaterial) of Japan using an Intel(R) Xeon(R) CPU E5-2687W 0 @ 3.10GHz with 64GB RAM running Microsoft Windows 8.1 Enterprise. This computer took about 1 hour and 32 minutes to complete the primality test using LLR. Naoki is a member of the Doshisha University team.


For more details, please see the official announcement.


11 May 2015 | 1:04:24 UTC · Comment


GFN-Short CUDA tasks suspended
I have suspended the GFN-Short CUDA tasks for Nvidia GPUs. If you were previously using the GFN-Short CUDA app, please select the GFN-Short OpenCL app for Nvidia instead.

The CUDA app has a lower B limit than either the OpenCL or CPU apps, and we've reached the point where CUDA tasks might start failing.

GFN-WR and PPS-Sieve CUDA apps are not affected by this change.
1 May 2015 | 13:08:37 UTC · Comment


321 Mega Prime! (2015 Edition)
On 13 March 2015, 19:55:59 UTC, PrimeGrid’s 321 Prime Search project found the mega prime:

3*2^11731850-1

The prime is 3,531,640 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 12th overall. This is the largest known 321 mega prime and the largest prime found to date at PrimeGrid!

The discovery was made by Karsten Klopffleisch (KarstenK) of Germany using an Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz with 16 GB RAM running Linux. This computer took about 18 hours and 33 minutes to complete the primality test using LLR.

The prime was verified on 18 March 2015 18:17:44 UTC, by Thomas Gbenro (dagee) of Germany using an Intel(R) Core(TM) i5-2500 CPU @ 3.30GHz with 4 GB RAM running Microsoft Windows 7 Enterprise. This computer took about 12 hours and 16 minutes to complete the primality test using LLR. Thomas is a member of the BOINC@Frankfurt Team.

For more details, please see the official announcement.

13 Apr 2015 | 1:01:19 UTC · Comment


27 Mega Prime!
On 9 March 2015, 17:49:18, PrimeGrid’s 27121 Prime Search, through PRPNet and in collaboration with the 12121 Search (k=27 sister project), has found the mega prime:

27*2^5213635+1

The prime is 1,569,463 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 38th overall.

The discovery was made by Hiroyuki Okazaki (zunewantan) of Japan using an Intel(R) Xeon(R) CPU E5-2648L 0 @ 1.80GHz Processor with 64GB RAM, running Microsoft Windows 7 Ultimate. This computer took about 5 hours and 5 minutes to complete the primality test using LLR. Hiroyuki is a member of the Aggie The Pew team.

For more details, please see the official announcement.


31 Mar 2015 | 2:26:14 UTC · Comment


Fermat Divisor!
On 13 February 2015 16:10:21 UTC, PrimeGrid's Proth Prime Search project found a prime Fermat divisor:

267*2^2662090+1 Divides F(2662088)

The prime is 801,372 digits long and entered Chris Caldwell's The Largest Known Primes Database ranked 3rd for prime Fermat divisors and 212th overall.

The discovery was made by Jay Parangalan (stellarfirefly) of the United States using an Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz with 32GB RAM running Microsoft Windows 7 Ultimate. This computer took about 2 hours 23 minutes to complete the primality test using LLR.

The prime was verified on 14 February 2015 by user Lee of the United States using an Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz with 16GB RAM running Microsoft Windows 8.1 Professional. This computer took about 2 hours 1 minute to complete the primality test using LLR.

For more details, please see the official announcement.

22 Feb 2015 | 20:15:26 UTC · Comment


Another PPS Mega Prime!
On 14 February 2015, 18:24:10 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

113*2^3437145+1

The prime is 1,034,686 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 108th overall.

The discovery was made by Evelyn Chew (Crackenback) of Australia using an Intel(R) Pentium(R) CPU G3220 @ 3.00GHz with 4GB RAM running Microsoft Windows 7 Enterprise. This computer took about 3 hours 1 minute to complete the primality test using LLR. Evelyn is a member of the BOINC@AUSTRALIA team.

The prime was verified on 15 February 2015, 10:52:20 UTC, by Grzegorz Roman Granowski (For the Universe ( Apaszko-Kaszkiety)) of Poland using an Intel(R) Xeon(R) CPU E5-2690 0 @ 2.90GHz with 16GB RAM running Microsoft Windows 7 Professional. This computer took about 7 hours and 45 minutes to complete the primality test using LLR. Grzegorz is a member of the BOINC@Poland team.


For more details, please see the official announcement.

22 Feb 2015 | 19:58:45 UTC · Comment


New GFN and GFN-WR 3.07 (3.2.6) apps released
I just put a new version of all builds of the Genefer app into production on the BOINC server. This is BOINC app version 3.07, and corresponds to Genefer 3.2.6.

Its primary change is to correct a potential memory corruption problem that could occur when resuming from a checkpoint. This only has been shown to occur under specific testing conditions and we don't believe it was ever a problem in production, and we're not worried about the validity of past results. (It would have been caught by the normal double checking if it did occur.)

There may also be a small speed increase in some of the builds,

If you encounter any problems, please report them in the Genefer 3.2.6 testing thread. Thank you!

11 Feb 2015 | 13:59:53 UTC · Comment


PPS MEGA Prime of the Month!
On 1 February 2015, 16:49:00 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

159*2^3425766+1

The prime is 1,031,261 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 107th overall.

The discovery was made by Evelyn Chew (Crackenback) of Australia using an Intel(R) Core(TM) i5-4670 CPU @ 3.40GHz with 8GB RAM running Microsoft Windows 7 Enterprise. This computer took about 1 hour 31 minutes to complete the primality test using LLR. Evelyn is a member of the BOINC@AUSTRALIA team.

The prime was verified on 1 February 2015, 19:11:39 UTC, by Matt Jurach (mattozan) of the United States using an Intel(R) Core(TM) i7-4500U CPU @ 1.80GHz with 16GB RAM running Microsoft Windows 8.1. This computer took about 6 hours and 9 minutes to complete the primality test using LLR. Matt is a member of the Aggie The Pew team.


For more details, please see the official announcement.

3 Feb 2015 | 3:24:18 UTC · Comment


ESP Mega Prime!
On 6 January 2015, 11:24:47 UTC, PrimeGrid’s Extended Sierpinski Problem Prime Search found the Mega Prime:

161041*2^7107964+1

The prime is 2,139,716 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 23rd overall. It eliminates k=161401; 11 k's remain in the Extended Sierpinski Problem.

The discovery was made by Martin Vanc (vmv) of the Czech Republic using an Intel(R) Core(TM) i5-4440 CPU @ 3.10GHz with 4GB RAM running Microsoft Windows 7. This computer took about 18 hours 9 minutes to complete the primality test using LLR. Martin is a member of the Czech National Team.

The prime was verified on 7 January 2015, 00:34:44 UTC, by Stefan Hofacker (shofacker) of Germany using an Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz with 32GB RAM running Microsoft Windows 7 Professional. This computer took about 22 hours and 19 minutes to complete the primality test using LLR. Stefan is a member of the SETI.Germany team.


For more details, please see the official announcement.

17 Jan 2015 | 16:17:21 UTC · Comment


Another PPS Mega Prime!
On 7 January 2015, 1:57:29 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

245*2^3411973+1

The prime is 1,027,109 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 107th overall.

The discovery was made by Rick Channing (Rick) of the United States using an Intel(R) Core(TM) i5 CPU 750 @ 2.67GHz with 4GB RAM running Microsoft Windows 7 Home Premium. This computer took about 3 hour 38 minutes to complete the primality test using LLR. Rick is a member of the SETI.USA team.

The prime was verified on 7 January 2015, 11:33:36 UTC, by John Christy (John Christy) of the United States using an Intel(R) Xeon(R) CPU E31220 @ 3.10GHz with 8GB RAM running Linux. This computer took about 1 hour and 35 minutes to complete the primality test using LLR. John is a member of the USA team.


For more details, please see the official announcement.

16 Jan 2015 | 3:21:34 UTC · Comment


PPS MEGA Prime Found!
On 6 January 2015, 18:51:43 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

177*2^3411847+1

The prime is 1,027,071 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 107th overall.

The discovery was made by William Darney (William J. Darney (G46VW)) of the United States using an AMD Phenom(tm) II X6 1090T with 16GB RAM running Microsoft Windows 7 Professional. This computer took about 3 hour 42 minutes to complete the primality test using LLR. William is a member of the LinusTechTips_Team team.

The prime was verified on 6 January 2015, 23:32:13 UTC, by Michael Becker (Nasicus) of Germany using an Intel(R) Xeon(R) CPU E5-2650 v2 @ 2.60GHz with 32 GB RAM running Microsoft Windows Server 2012 R2 Standard Edition. This computer took about 2 hours and 49 minutes to complete the primality test using LLR. Michael is a member of the Crunchers@Freiburg team.


For more details, please see the official announcement.

14 Jan 2015 | 1:17:59 UTC · Comment


Exact BOINC task timing
If you have a relatively new BOINC client, you may notice that BOINC suddenly got better at estimating how much longer your PrimeGrid tasks will take to finish. BOINC will now ignore its internal estimate of how long the task should take and will rely only on the elapsed time divided by the percentage completed (i.e., what we always tell you to do if you want a good estimate.)

For this to work, you need (I believe) BOINC client 7.3.18 or later. The 7.2.xx clients that many still use do not support this feature.

Please note that this only affects the "Remaining (estimated)" display for tasks that have already started. Tasks that have not started are not affected and may still show erroneous (or wildly erroneous) times. It also won't have any affect on BOINC deciding to download too much or too little work because its time estimates are off. Only started tasks are affected by this new feature.

(The is the same functionality you can manually set yourself by using the <fraction_done_exact> tag in app_config.xml.)
2 Jan 2015 | 21:24:26 UTC · Comment


PPS MEGA Prime Found!
On 1 December 2014, 8:02:57 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

255*2^3395661+1

The prime is 1,022,199 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 107th overall.

The discovery was made by John Christy (John Christy) of the United States using an Intel(R) Xeon(R) CPU E31220 @ 3.10GHz with 8GB RAM running Linux. This computer took about 1 hour 27 minutes to complete the primality test using LLR. John is a member of the USA team.

The prime was verified on 3 December 2014, 21:47:43 UTC, by Scott Bedenbaugh (PixelSmasher8) of the United States using an AMD FX(tm)-8320 Eight-Core Processor with 16 GB RAM running Microsoft Windows 7 Professional. This computer took about 4 hours and 54 minutes to complete the primality test using LLR. Scott is a member of the SEACOAST -- SouthEAst COalition of Alien Signal Trackers team.


For more details, please see the official announcement.
13 Dec 2014 | 16:09:14 UTC · Comment


321 Mega Prime!
On 22 November 2014, 14:46:02 UTC, PrimeGrid’s 321 Prime Search project found the mega prime:

3*2^11484018-1

The prime is 3,457,035 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 12th overall. This is the largest known 321 mega prime and the largest prime found to date at PrimeGrid!

The discovery was made by Serhiy Gushchak (Sergyg) of the Ukraine using an Intel(R) Core(TM) i3-2120 CPU @ 3.30GHz with 12 GB RAM running Microsoft Windows 7 Ultimate. This computer took about 27 hours and 2 minutes to complete the primality test using LLR. Serhiy is a member of the Ukraine Team.

The prime was verified on 24 November 2014 11:24:03 UTC, by Thomas Schulze Curly of Germany using an Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz with 16 GB RAM running Microsoft Windows 7 Professional. This computer took about 32 hours and 56 minutes to complete the primality test using LLR. Thomas is a member of the BOINCStats Team.

For more details, please see the official announcement.
9 Dec 2014 | 21:03:50 UTC · Comment


Winter Solstice Challenge starts Dec 18th 23:03 UTC
Dear all,

The end of the year is drawing closer and this is traditionally marked with the winter solstice challenge here at PrimeGrid. As in previous years we would like to invite everyone to join us in this celebration of tidings of comfort and joy by sieving away for the Proth Prime Search. The challenge will start on Dec 18 23:03 UTC and last for 72 hours.

For more information, cheery banter and general merrymaking please join us on the discussion board.

We hope to see you there and please do spread the word :)
8 Dec 2014 | 22:10:17 UTC · Comment


SR5 Mega Prime!
On 18 October 2014, 6:18:40 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=109208 by finding the mega prime:

109208*5^1816285+1

The prime is 1,269,534 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 59th overall. This is the largest known base 5 mega prime. 37 k's now remain in the Sierpinski Base 5 Problem.

The discovery was made by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM)2 Quad CPU Q6700 @ 2.66GHz with 8GB RAM running Windows 7 Enterprise. This computer took about 11 hours and 3 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

The prime was verified on 21 October 2014, 6:19:48 UTC, by Tod Slakans (NeoMetal*) of the United States using an Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz with 8GB RAM running Microsoft Windows 7 Home Premium. This computer took about 3 hours and 11 minutes to complete the primality test using LLR. Tod is a member of the Sicituradastra. team.

For more details, please see the official announcement.


28 Oct 2014 | 1:02:20 UTC · Comment


PPS MEGA Prime Found!
On 23 September 2014, 17:30:36 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

179*2^3371145+1

The prime is 1,014,819 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 105th overall.

The discovery was made by John Christy of the United States using an Intel(R) Xeon(R) CPU E31220 @ 3.10GHz with 8GB RAM running Linux. This computer took about 1 hour 27 minutes to complete the primality test using LLR. John is a member of the USA team.

The prime was verified on 23 September 2014, 21:47:43 UTC, by Patrick Martin (ptube974) of the United States using an Intel(R) Core(TM) i7-4770K CPU @ 3.50GHz with 8 GB RAM running Linux. This computer took about 4 hours and 22 minutes to complete the primality test using LLR. Patrick is a member of the Overclock.net team.

The prime was reported to The Largest Known Primes Database by Patrick following a period of non-reporting by the discoverer .

For more details, please see the official announcement.


19 Oct 2014 | 18:00:34 UTC · Comment


Another TRP Prime!
On 4 October 2014, 22:32:24 UTC, PrimeGrid’s The Riesel Problem project eliminated k=502573 by finding the mega prime:

502573*2^7181987-1

The prime is 2,162,000 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 20th overall. This is the largest prime found in The Riesel Problem and PrimeGrid's 14th elimination. 50 k's now remain.

The discovery was made by Denis Iakovlev (Goliaf-RS) of Russia using an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz with 8 GB RAM running Windows 7 Professional. This computer took about 19 hours and 40 minutes to complete the primality test using LLR. Denis is a member of the Russia Team.

The prime was verified on 5 October 2014, 11:48:03 UTC, by Russell Mathers (Russ) of the United Kingdom using an Intel(R) Core(TM) i7-3960X CPU @ 3.30GHz with 16 GB RAM running Microsoft Windows 7 Professional. This computer took about 18 hours and 46 minutes to complete the primality test using LLR.


For more details, please see the official announcement.




17 Oct 2014 | 0:45:28 UTC · Comment


TRP Mega Prime!
On 2 October 2014, 3:02:44 UTC, PrimeGrid’s The Riesel Problem project eliminated k=402539 by finding the mega prime:

402539*2^7173024-1

The prime is 2,159,301 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 20th overall. This is the largest prime found in The Riesel Problem and PrimeGrid's 13th elimination. 51 k's now remain.

The discovery was made by Walter Darimont (Walter Darimont) of Belgium using an Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz with 4 GB RAM running Linux. This computer took about 11 hours and 10 minutes to complete the primality test using LLR. Walter is a member of the Aggie the Pew Team.

The prime was verified on 2 October 2014, 9:51:42 UTC, by Tom Greer (tng*) of the United States using an Intel(R) Xeon(R) CPU E5520 @ 2.27GHz with 24 GB RAM running Microsoft Windows 7 Professional. This computer took about 25 hours and 35 minutes to complete the primality test using LLR. Tom is a member of the Sicituradastra. Team.


For more details, please see the official announcement.
14 Oct 2014 | 11:31:41 UTC · Comment


SR5 Mega Prime!
On 21 September 2014, 18:43:31 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=325918 by finding the mega prime:

325918*5^1803339-1

The prime is 1,260,486 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 58th overall. This is the largest known base 5 mega prime. 79 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Jörg Meili (meilijo) of Switzerland using an Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz with 8GB RAM running Microsoft Windows 7 Home Premium. This computer took about 20 hours and 51 minutes to complete the primality test using LLR. Jörg is a member of the Aggie the Pew team.

The prime was verified on 1 October 2014, 12:57:59 UTC by Yegor Ryabchikov (Yegor001) of Russia using an Intel(R) Core(TM) i5 CPU 760 @ 2.80GHz with 2GB RAM running Microsoft Windows 7 Home Basic. This computer took about 133 hours 16 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
12 Oct 2014 | 20:51:24 UTC · Comment


AVG interference with BOINC
It seems that AVG has been randomly flagging some of our executables as having an identity theft trojan, and removing them from the BOINC directory. It only happens occasionally and is likely a bug in AVG. The executables themselves are fine and pose no threat.

If you use AVG, I *strongly* recommend configuring AVG to ignore the C:\ProgramData\BOINC folder, and also disable identify protection. You can't tell the identity protection system to ignore a folder, so you have to completely disable it.

Or switch to a different anti-virus product.

This can be discussed here.
30 Sep 2014 | 14:45:50 UTC · Comment


PrimeGrid is back!
We had a bit of an exciting weekend, and what was originally a planned maintenance downtime of a few hours turned into a two day "rebuild and upgrade everything" challenge.

We're back up now, and once the DNS name for the new server propagates throughout the Internet everyone should be able to connect again.

For more information, please see this discussion.
29 Sep 2014 | 17:41:44 UTC · Comment


World Animal Day Challenge starts October 4th, 18:00 UTC
People have always had an interesting relationship with animals. We hunt them for food, we keep livestock for food too but we also use them for labor and keep them as pets and love them like family. In honor of this relationship there is a special day, World Animal Day. To mark this day, PrimeGrid invites every one to participate in the challenge starting at 18:00 utc on October 4th, 2014 it will run for five days until October 9th, 2014, 18:00 UTC

For questions, banter, information you can go to this thread in our forums.

Please do spread the word and join the fun!
24 Sep 2014 | 15:08:52 UTC · Comment


SR5 Mega Prime!
On 17 August 2014, 13:00:59 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=133778 by finding the mega prime:

133778*5^1785689+1

The prime is 1,248,149 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 56th overall. This is the largest known base 5 mega prime. 38 k's now remain in the Sierpinski Base 5 Problem.

The discovery was made by Guo Hua Miao (前朝遗少) of China using an Intel Xeon(R) CPU E5-4617 @ 2.90GHz with 504GB RAM running Linux. This computer took about 27 hours and 9 minutes to complete the primality test using LLR. Guo is a member of the Team China team.

For more details, please see the official announcement.
12 Sep 2014 | 18:32:27 UTC · Comment


PRPNet server upgraded!
The new and improved PRPNet server is now online.

Information and discussion can be found here.
6 Sep 2014 | 2:55:49 UTC · Comment


27 Mega Prime!
On 22 August 2014, 4:33:59 UTC, PrimeGrid’s 27121 Prime Search, through PRPNet and in collaboration with the 12121 Search (k=27 sister project), has found the mega prime: 27*2^4583717-1

The prime is 1,379,838 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 48th overall.

The discovery was made by Hans Joachim Böhm (SEARCHER) of Germany using an Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz Processor with 4GB RAM, running Microsoft Windows 7 Ultimate. This computer took just over 15 hours 24 minutes to complete the primality test using LLR. Hans is a member of the SETI.Germany team.

For more details, please see the official announcement.
5 Sep 2014 | 0:29:32 UTC · Comment


PPS-Sieve ATI apps and GFN MAC ATI apps turned back on.
A little late on the announcement, but we've fixed and corrected two apps that had to be taken offline earlier this year.

The ATI/AMD version of the PPS-Sieve app was put back online a couple of days ago. More details can be found in this thread.

The GFN (short and WR) ATI/AMD Mac apps were put back into service last month. More details can be found here.

We are very grateful for the volunteer developers, builders, and testers who put so much effort into fixing those apps. Thanks!
19 Aug 2014 | 15:39:32 UTC · Comment


New MEGA prime and World Record Fermat Divisor!
On 25 July 2014, 8:47:48 UTC, PrimeGrid’s Mega Prime Search found a world record prime Fermat divisor:

193*2^3329782+1 Divides F(3329780)

The prime is 1,002,367 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for prime Fermat divisors and 98th overall. It is also a new record for "weighted" prime Fermat divisors.

The discovery was made by Raymond Ottusch (RaymondFO*) of the United States using an Intel Core i7-3930K CPU @ 3.20GHz with 12 GB RAM running Microsoft Windows 7 Professional. This computer took about 1 hour 11 minutes to complete the primality test using LLR. Raymond is a member of the Sicituradastra. team.

The prime was verified on 28 Jul 2014, 5:02:21 UTC by John Christy (John Christy) of the United States using an Intel Xeon CPU E31220 @ 3.10GHz with 8 GB RAM running Linux. This computer took about 1 hour and 24 minutes to complete the primality test using LLR. John is a member of the USA team.

For more details, please see the official announcement.
8 Aug 2014 | 16:39:46 UTC · Comment


New MEGA prime found!
On 24 July 2014, 3:59:36 UTC, PrimeGrid’s Mega Prime Search found the Mega Prime:

129*2^3328805+1

The prime is 1,002,073 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 98th overall.

The discovery was made by Eric Clifton (Grandpa) of the United States using an Intel Core i7-2700K CPU @ 3.50GHz with 16GB RAM running Microsoft Windows 7 Professional. This computer took about 46 minutes 7 seconds to complete the primality test using LLR. Eric is a member of the [H]ard|OCP team.

In addition to being verified internally, the prime was also verified on 27 July 2014, 3:34:11 UTC, by Vladislav Ketamino (ThrasherX-17) of the Ukraine using a Genuine Intel CPU @ 1.60GHz with 8 GB RAM running Microsoft Windows 7 Ultimate. This computer took about 2 hours and 18 minutes to complete the primality test using LLR. Vladislav is a member of the Keep The Fire Alive! team.

For more details, please see the official announcement.

7 Aug 2014 | 0:12:35 UTC · Comment


New SR5 Mega Prime!
On 23 July 2014, 5:52:51 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=24032 by finding the mega prime:

24032*5^1768249+1

The prime is 1,235,958 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 54th overall. This is the largest known base 5 mega prime. 39 k's now remain in the Sierpinski Base 5 Problem.

The discovery was made by Hiroyuki Okazaki (zunewantan) of Japan using an Intel Xeon CPU E31220 @ 3.10GHz with 4GB RAM running Microsoft Windows Server 2008. This computer took about 3 hours and 16 minutes to complete the primality test using LLR. Hiroyuki is a member of the Aggie The Pew team.

The prime was verified on 23 July 2014, 8:30:46 UTC, by Vincent Ollivier (MohMan) of Canada using an Intel Core i7-3770 CPU @ 3.40GHz with 8 GB RAM running Microsoft Windows 7 Professional. This computer took about 6 hours and 38 minutes to complete the primality test using LLR. Vincent is a member of the SUPINFO team.

For more details, please see the official announcement.

6 Aug 2014 | 2:10:42 UTC · Comment


27 Mega Prime
On 17 July 2014, 2:36:47 UTC, PrimeGrid’s 27121 Prime Search, through PRPNet and in collaboration with the 12121 Search (k=27 sister project), has found the mega prime: 27*2^4542344-1

The prime is 1,367,384 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 47th overall.

The discovery was made by Scott Brown (Scott Brown) of the United States using an AMD Phenom(tm) II X6 1055T Processor with 4GB RAM, running Microsoft Windows 7 Enterprise. . This computer took just over 8 hours 25 minutes to complete the primality test using LLR. Scott is a member of the Duke University Team.

For more details, please see the official announcement.
6 Aug 2014 | 0:56:27 UTC · Comment


Genefer 3.2.2 released
The latest version of Genefer, v. 3.2.2, has been released and is live for both short and World Record tasks. Some notable changes:

1) The OpenCl and CPU apps are significantly faster than the previous versions.

2) It is likely that the OpenCL app is now faster than the CUDA app on any Nvidia GPU, but especially on newer (Kepler or later, 6xx or newer) GPUs. On the app selection page, the OpenCL app now appears before the CUDA app. NOTE: On Nvidia cards, the OpenCL driver hogs a CPU core. If you have an Nvidia GPU, you may chose between the faster app (OpenCL) or that app that uses very little CPU (CUDA).

3) The CPU app now supports the FMA3 instructions on Intel Haswell CPUs, which makes them even faster.

4) The bug in the Mac ATI app has been fixed.

Please see this thread for more information and discussion.
27 Jul 2014 | 21:59:28 UTC · Comment


GFN n=262144 Sieve (re)Starting
We're (re)starting manual sieving on GFN n=262144. Please see this message for more information. 20 Jul 2014 | 0:07:49 UTC · Comment


Mega Prime Search Now Running on BOINC
We have moved the PRPNet MEGA project over to the BOINC server. To run PPS-Mega, just select the PPS-Mega (LLR) app in your PrimeGrid Preferences.

The PPS-Mega project is part of our Proth Prime Search (PPS) project. There's now three ranges of PPS tests:

PPSE: Currently around n=1.3M and about 400K digits
PPS: Currently around n=2.1M and about 650K digits
Mega: 3.322M < n < 3.6M and just over 1 million digits

The PPS-Mega tasks take about an hour on the fastest computers (Intel Haswell CPUs). This project is ideal for finding mega primes. In all of history, only 97 mega primes have ever been found -- but PrrimeGrid has already found 17 so far this year.

Will you discover the next mega prime?
18 Jul 2014 | 1:37:20 UTC · Comment


New MEGA prime found!
On 4 July 2014 21:42:34 UTC, PrimeGrid’s Mega Prime Search, through PRPNet, found the Mega Prime:

35*2^3587843+1

The prime is 1,080,050 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 69th overall.

The discovery was made by Peter Tibbott (TroubledBunny) of the United Kingdom using an Intel i5-3570K CPU @ 3.40GHz with 8GB RAM running Microsoft Windows 7 Professional. This computer took about 1 hour 24 minutes to complete the primality test using LLR. Peter is a member of the UK BOINC Team.

The prime was verified internally.

For more details, please see the official announcement.
16 Jul 2014 | 2:27:47 UTC · Comment


Another New SR5 Prime Found!
On 27 June 2014, 20:20:40 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=138172 by finding the mega prime:

138172*5^1714207-1

The prime is 1,198,185 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 54th overall. This is the largest known base 5 mega prime. 80 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Walter Darimont (Walter Darimont) of Belgium using an Intel Core i7-3770 CPU @ 3.40GHz with 3.8GB RAM running Linux. This computer took about 18 hours and 25 minutes to complete the primality test using LLR. Walter is a member of the Aggie The Pew team.

The prime was verified on 28 June 2014 13:08:49 UTC, by Scott Brown (Scott Brown) of the United States using an Intel Core2 CPU 6600 @ 2.40GHz with 4 GB RAM running Microsoft Windows 7 Enterprise. This computer took about 38 hours and 32 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

For more details, please see the official announcement.

15 Jul 2014 | 22:10:05 UTC · Comment


New SR5 Mega Prime Found!
On 19 June 2014, 3:36:34 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=22478 by finding the mega prime:

22478*5^1675150-1

The prime is 1,170,884 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 54th overall. This is the largest known base 5 mega prime. 81 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Guo Hua Miao (前朝遗少) of China using an Intel Xeon CPU E5-4617 @ 2.90GHz with 516GB RAM running Linux. This computer took about 25 hours and 24 minutes to complete the primality test using LLR. 前朝遗少 is a member of Team China.

The prime was verified internally.

For more details, please see the official announcement.

15 Jul 2014 | 20:19:54 UTC · Comment


And Another New MEGA prime found!
On 10 June 2014 20:37:03 UTC, PrimeGrid’s Mega Prime Search, through PRPNet, found the Mega Prime:

35*2^3570777+1

The prime is 1,074,913 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 66th overall.

The discovery was made by Robert Lacroix (composite) of Canada using an Intel(R) Xeon E5-2697 @ 2.7 GHz with 64GB RAM running Linux. This computer took about 1 hour 40 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
30 Jun 2014 | 1:27:45 UTC · Comment


New MEGA prime found!
On 10 June 2014 5:22:14 UTC, PrimeGrid’s Mega Prime Search, through PRPNet, found the Mega Prime:

33*2^3570132+1

The prime is 1,074,719 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 66th overall.

The discovery was made by Fabrice Le Foulher (JackTheSkipper) of France using an Intel(R) Core(TM) i7-2600k CPU @ 3.40GHz with 10GB RAM running Windows 7 Home Premium. This computer took about 1 hour 45 minutes to complete the primality test using LLR. Fabrice is a member of the L'Alliance Francophone team.

For more details, please see the official announcement.

30 Jun 2014 | 1:20:54 UTC · Comment


New BOINC Sub-Project: ESP Sieve
We have re-opened the suspended PSP sieve to do new sieving work for ESP, and renamed it the Sierpinski (ESP/PSP/SoB) Sieve. The reopened sieve uses the same statistics and badges as the PSP sieve.

For many people, this is a chance to get a new badge, and for others it is an opportunity to improve upon their existing PSP Sieve badge.

For more information, or to discuss the ESP Sieve, please see this forum thread.
29 Jun 2014 | 12:44:46 UTC · Comment


PPS-Sieve ATI app turned off temporarily
We have temporarily turned off the ATI apps for PPS-Sieve. We're going to need help with building and testing the fixed app.

Please see this thread for more information.
16 Jun 2014 | 13:10:31 UTC · Comment


New BOINC Sub-Project: ESP
We've just opened up the ESP (Extended Sierpinski Problwm) project on BOINC. There's a brand new set of ESP badges, so feel free to come and help solve the Extended Sierpinski Problem and also fill out your set of badges!

For more information please see this forum, and feel free to ask questions or discuss ESP in this thread.
7 Jun 2014 | 22:30:20 UTC · Comment


New MEGA prime found!
On 6 May 2014 13:40:30 UTC, PrimeGrid’s Mega Prime Search, through PRPNet, found the Mega Prime:

93*2^3544744+1

The prime is 1,067,077 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 69th overall.

The discovery was made by Michał Gasewicz (Genn) of Poland using an Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz with 8GB RAM running Linux. This computer took about 1 hour 39 minutes to complete the primality test using LLR. Michał is a member of the BOINC@Poland team.

For more details, please see the official announcement.

30 May 2014 | 13:57:57 UTC · Comment


New GFN Apps
Version 3.2.0 of all flavors of the GFN and GFN-WR apps have been installed. No action is necessary on your part; you will automatically receive the correct app for your computer.

It is no longer necessary to manually select the correct CPU app (SSE2/SSE3/AVX). This version does not yet support Haswell/FMA3/AVX2, but that's coming in the near future.

For more information, or to discuss the new apps, please see this thread.
28 May 2014 | 21:44:01 UTC · Comment


SR5 Double Check Starting
In roughly 24 hours time we are gong to start a full double check of prior SR5 work. Initially, tasks will be much shorter and will take about 1 minute on the fastest computers. I expect the double check will take about 2 months to complete.

For more information, or to leave a comment, please see this discussion thread.
5 May 2014 | 22:19:41 UTC · Comment


Yet another SR5 prime discovered!
On 25 April 2014, 21:06:16 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=326834 by finding the mega prime:

326834*5^1634978-1

The prime is 1,142,807 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 56th overall. This is the largest known base 5 mega prime. 82 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM) i5-2410M CPU @ 2.30GHz with 6GB RAM running Microsoft Windows 7 Home Premium. This computer took about 44 hours and 32 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

The prime was verified on 26 April 2014 15:50:21 UTC, by Alejandro Kurtz (Alejandro) of Spain using an Intel(R) Core(TM) i5-2500 CPU @ 3.30GHz with 5.5 GB RAM running Microsoft Windows 7 Professional. This computer took about 13 hours and 28 minutes to complete the primality test using LLR. Alejandro is a member of the CANAL@Boinc team.

For more details, please see the official announcement.
27 Apr 2014 | 16:05:11 UTC · Comment


Another New SR5 Prime Found!
On 9 April 2014, 18:33:30 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=207394 by finding the mega prime:

207394*5^1612573-1

The prime is 1,127,146 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 59th overall. This is the largest known base 5 mega prime. 83 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Honza Cholt (Honza) of the Czech Republic using an Intel(R) Xeon(R) CPU E5-2609 0 @ 2.40GHz with 12GB RAM running Microsoft Windows Server 2008. This computer took about 16 hours and 5 minutes to complete the primality test using LLR. Honza is a member of the BOINC.SK team.

For more details, please see the official announcement.



26 Apr 2014 | 16:10:28 UTC · Comment


PRPNet GFN ports reopened!
The four GFN ports on PRPNet have been reopened. You'll need to be using PRPNet 5.3.0, including both the new versions of prpclient and genefer, to run GFN.

Due to the potential for erroneous results having been previously returned, some of the GFN candidates on all four ports will be retested. Most of the retests are on the GFN65536 port.

(This post applies only to our PRPNet GFN projects. The BOINC GFN projects are not affected.)
26 Apr 2014 | 0:53:41 UTC · Comment


New SR5 Mega Prime Found!
On 9 April 2014, 9:13:42 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=104944 by finding the mega prime:

104944*5^1610735-1

The prime is 1,125,861 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 59th overall. This is the largest known base 5 mega prime. 84 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Brian Smith (Sherlock Holmes) of Germany using an Intel(R) Core(TM)2 Duo CPU T9800 @ 2.93GHz with 4GB RAM running Microsoft Windows 7 Professional. This computer took about 27 hours and 21 minutes to complete the primality test using LLR.

The prime was verified on 9 April 2014 15:47:16 UTC, by Dave Sunderland (DaveSun) of the United States using an Intel(R) Core(TM)2 Quad CPU Q9300 @ 2.50GHz with 4 GB RAM running Microsoft Windows XP Professional. This computer took about 30 hours and 46 minutes to complete the primality test using LLR.

For more details, please see the official announcement.

19 Apr 2014 | 18:40:27 UTC · Comment


FMA3 LLR going live on all LLR projects
Early Sunday, April 20th UTC (Saturday afternoon or evening in the western hemisphere) we are going to install the new FMA3 (aka AVX2) version of LLR on the remaining LLR projects.

Especially on Intel Haswell CPUs, but to some extent also on Ivy Bridge and Sandy Bridge CPUs, this new app is significantly faster. It also consumes more power, and generates more heat. Please make sure your computer is up to running the new app.

In general, expect the highest temperatures with shorter projects (PPSE, SGS, and PPS) while longer projects such as SoB and PSP will run slightly less hot.

Information and discussion about the new LLR app can be found in this thread.

18 Apr 2014 | 22:08:42 UTC · Comment


Badge threshold changes
For longer than I can remember, some of PrimeGrid's badges have required twice the credit as other badges. The reason for that difference long ago ceased to be relevant and so we have lowered the required credit for those badges to be the same as all the others. Therefore, you may have gone up a badge level in those projects. This change also applies retroactively to closed or suspended projects.

The affected projects are all the sieves, AP26, GFN, and PSA.

Discussion of this topic is in this thread.
9 Apr 2014 | 12:11:12 UTC · Comment


Another MEGA Prime Found
On 28 March 2014 21:32:37 UTC, PrimeGrid’s Mega Prime Search, through PRPNet, found the Mega Prime: 51*2^3490971+1

The prime is 1,050,889 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 69th overall.

The discovery was made by Stefan Larsson (288larsson) of Sweden using an Intel(R) Core(TM) i7-4930K CPU @ 3.40GHz with 16GB RAM running Microsoft Windows 8.1. This computer took just over 1 hour 13 minutes to complete the primality test using LLR. Stefan is a member of the Sicturadastra team.

For more details, please see the official announcement.

5 Apr 2014 | 14:51:12 UTC · Comment


MEGA Prime Found
On 28 March 2014 19:57:24 UTC, PrimeGrid’s Mega Prime Search, through PRPNet, found the Mega Prime: 87*2^3496188+1

The prime is 1,052,460 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 70th overall.

The discovery was made by Gary Craig (Gary Craig) of the United States using an Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz with 4GB RAM running Linux. This computer took just over 1 hour 11 minutes to complete the primality test using LLR. Gary is a member of the Aggie The Pew team.

For more details, please see the official announcement.
5 Apr 2014 | 14:44:51 UTC · Comment


World record SR5 prime discovered!
On 21 March 2014, 13:39:54 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=330286 by finding the mega prime:

330286*5^1584399-1

The prime is 1,107,453 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 57th overall. This is the largest known base 5 mega prime. 85 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz with 4GB RAM running Microsoft Windows 7 Enterprise. This computer took about 35 hours and 55 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

The prime was verified on 23 March 2014 10:55:21 UTC, by Baneus of Germany using an AuthenticAMD Quad-Core AMD Opteron(tm) Processor 2356 with 64 GB RAM running Linux. This computer took about 73 hours and 11 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
24 Mar 2014 | 17:19:26 UTC · Comment


Android Support Temporarily Disabled
The Android TRP-Sieve application has been disabled while we investigate a problem with this build of the sieve program.

I do not yet have an ETA for when a fix will become available. If you're currently running a task (or tasks) on Android you can complete and return them. However, no new tasks will be sent to Android devices until this problem is resolved.

I apologize for any inconvienence this may cause.

Discussion about the Android app is ongoing in this thread.
10 Mar 2014 | 19:50:35 UTC · Comment


False Google malware alert
Earlier today Google's Chrome browser started blocking access to some forum posts on PrimeGrid's website. Most importantly, there is no malware at PrimeGrid and it is 100% safe to access our website.

What happened is not specific to PrimeGrid, and in fact isn't specific to BOINC. This false report likely affected numerous tech forums across the entire Internet.

Many people use CPU-Z to monitor their computers, and also use their "validation" system to register and show off their computers. The website used by CPU-Z for this validation is "valid [dot] canardpc [dot] com" and that's the website that Google thinks is malicious. (I don't actually know if it is or not. I suspect it's fine.)

Because many people put a link to their CPU-Z validations in either their signatures or in posts, any forum webpage with such a link now gets blocked by Google as malicious.

Just to be perfectly clear, even if CPU-Z's website WAS malicious, merely viewing the PrimeGrid forum pages would not pose any risk.

While researching this problem on the web, I discovered that this is not the first time CPU-Z has been erroneously flagged by Google as being malicious. It's therefore reasonable to expect that it also won't be the last. In order to prevent this from happening in the future, effective immediately links or references to the CPU-Z validation site are prohibited in both forum posts and in signatures. The server will automatically remove posts or signatures that reference valid [dot] canardpc [dot] com. Four signatures and a handful of posts had to be removed.
7 Mar 2014 | 18:45:05 UTC · Comment


Consumer-grade UPSs and new computers
If you use a consumer grade UPS (Uninterruptable Power Supply) to keep your computer running during momentary power glitches or short outages, you should probably read this thread:

Oops! Lesson learned about UPS and active PFC power supplies

(Discussion on this topic should be directed to that thread.)

In short, most of the inexpensive UPSs you would buy for your home are incompatible with newer computer power supplies because the power supply uses something called "Active PFC". If the UPS switches to battery power, the computer may shut off. In the worst case scenario, the UPS, the computer power supply, or other components of the computer may be damaged.

The problem is that most inexpensive UPSs don't produce a true sine wave output, and that messes up the active PFC power supplies.

Business grade UPSs (such as APC's "Smart-UPS" line) produce pure sine wave outputs and work fine with new power supplies, but those start at around $300. The only consumer grade UPSs with true sine wave outputs that I'm aware of are from Cyberpower. They're a little more expensive, but much less than the business grade UPSs.

If you have a computer with a power supply that has active PFC, or if you might ever get one in the future, you don't want to use a UPS with "stepped" or "simulated" sine wave output. At best, the computer will shut off. At worst, you'll be buying new computer parts. Keep in mind that as time goes on, more and more power supplies will be using active PFC. It's a "green" technology, is good for the power grids, and is mandated by regulation in some jurisdictions, notably the EU.
3 Mar 2014 | 20:52:57 UTC · Comment


Double Top Secret Mystery Challenge starts March 1st 2014, 18:00 UTC
After 4 year long hiatus, PrimeGrid is once more offering a challenge on the Prime Sierpinski Problem subproject. The challenge will last 15 days and runs from March 1st, 2014 18:00 UTC to March 16th, 2014 18:00 UTC.

For more information, assistance and cheery banter please do join us on the forums in this thread
24 Feb 2014 | 15:56:43 UTC · Comment


GFN PRPNet ports temporarily shut down
We are investigating a software issue with the four GFN PRPNet ports which is affecting the quality of the results.

Until this issue is resolved, no new work will be sent out on any of the GFN ports.

Obviously, if you wish to do so, please feel free to crunch on the BOINC GFN-Short or GFN-WR projects instead while the problem with the PRPNet ports is being corrected.

If you happen to be using geneferocl 3.2.0-0beta with app_info on BOINC, please stop using the beta app. In at least some tests it's producing incorrect results and will fail validation.

For more information, please see this thread.
15 Feb 2014 | 14:47:16 UTC · Comment


Fix for running new AMD GPUs (r9 280x, etc.)
If you've been having trouble getting BOINC tasks on Primegrid or other projects for your new AMD r9 280x and similar GPUs, there may be a fix.

Please see this discussion for details.

In short, you'll need to upgrade to at least version 7.2.39 of the BOINC client (which can be downloaded here), and you'll need the AMD APP (which can be downloaded here.)
11 Feb 2014 | 16:22:25 UTC · Comment


Deja Vu: World Record SR5 Discovery
On 6 February 2014, 16:02:23 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=22934 by finding the mega prime:

22934*5^1536762-1

The prime is 1,074,155 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 61st overall. This is the largest known base 5 mega prime. 86 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Keishi Toda (yuyusuke@jisaku) of Japan using an Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz with 14GB RAM running Microsoft Windows 7 Home Premium. This computer took about 9 hours and 2 minutes to complete the primality test using LLR. Keishi is a member of the Team 2ch team.

This is the second world record base 5 SR5 mega prime Keishi has discovered in approximately one week's time!

The prime was verified on 2 February 2014 0:15:42 UTC, by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz with 4 GB RAM running Microsoft Windows 7 Enterprise. This computer took about 21 hours and 34 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

For more details, please see the official announcement.
9 Feb 2014 | 17:16:37 UTC · Comment


Another Record SR5 Prime!
On 31 January 2014, 9:53:06 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=178658 by finding the mega prime:

178658*5^1525224-1

The prime is 1,066,092 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 61st overall. This is the largest known base 5 mega prime. 87 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Keishi Toda (yuyusuke@jisaku) of Japan using an Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz with 14GB RAM running Microsoft Windows 7 Home Premium. This computer took about 19 hours and 59 minutes to complete the primality test using LLR. Keishi is a member of the Team 2ch team.

The prime was verified on 2 February 2014 0:15:42 UTC, by smmistak of the United States using an Intel(R) Core(TM) i7-2700K CPU @ 3.50GHz with 16 GB RAM running Microsoft Windows 7 Ultimate. This computer took about 59 hours and 27 minutes to complete the primality test using LLR.

For more details, please see the official announcement.

2 Feb 2014 | 21:07:30 UTC · Comment


Tour de Primes 2014
Just like the past five years, PrimeGrid is offering a little side challenge in February: the Tour de Primes. You can run any subproject you like, be it via our BOINC server or our PRPNet servers. Unlike the regular challenges, this one will not give you challenge points for the challenge leader board but you can win a unique badge.

For more information, questions and general good fun please join us on our forums in this thread.
29 Jan 2014 | 15:18:00 UTC · Comment


World Record 321 Mega Prime Found!
On 14 January 2014, 15:26:41 UTC, PrimeGrid’s 321 Prime Search project found the mega prime:

3*2^10829346+1

The prime is 3,259,959 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 12th overall. This is the largest known 321 mega prime and the largest prime found to date at PrimeGrid!

The discovery was made by Sai Yik Tang (tomakey) of Malaysia using an Intel(R) Core(TM) i5-2400 CPU @ 3.10GHz with 4 GB RAM running Microsoft Windows 7 Enterprise. This computer took about 17 hours and 40 minutes to complete the primality test using LLR.

The prime was verified on 14 January 2014 20:23:24 UTC, by schnabelt of Germany using an Intel(R) Pentium(R) CPU G850 @ 2.90GHz with 4 GB RAM running Microsoft Windows 7 Enterprise. This computer took about 22 hours and 47 minutes to complete the primality test using LLR.

For more details, please see the official announcement.


24 Jan 2014 | 4:08:03 UTC · Comment


New SR5 Mega Prime Found!
On 17 January 2014, 6:53:10 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=59912 by finding the mega prime:

59912*5^1500861+1

The prime is 1,049,062 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 66th overall. This is the largest known base 5 mega prime. 40 k's now remain in the Sierpinski Base 5 Problem.

The discovery was made by Raymond Ottusch (RaymondFO*) of the United States using an Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz with 24 GB RAM running Linux. This computer took about 3 hours and 41 minutes to complete the primality test using LLR. Raymond is a member of the Sicituradastra team.

The prime was verified on 17 January 2014 20:33:24 UTC, by Michael Wild (Tin Man) of the United Kingdom using an Intel(R) Core(TM) i5-2400 CPU @ 3.10GHz with 4 GB RAM running Darwin. This computer took about 2 hours and 50 minute to complete the primality test using LLR. Michael is a member of the BOINC@AUSTRALIA team.

For more details, please see the official announcement.



20 Jan 2014 | 12:52:57 UTC · Comment


New SR5 Mega Prime Found!
On 29 December 2013, 18:56:35 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=37292 by finding the mega prime:

37292*5^1487989+1

The prime is 1,040,065 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 65th overall. This is the largest known base 5 mega prime. 41 k's now remain in the Sierpinski Base 5 Problem.

The discovery was made by Stephen R. Cilliers (SteveRC) of South Africa using an Intel(R) Core(TM) i5-3230M CPU @ 2.60GHz with 8 GB RAM running Microsoft Windows 8.1. This computer took about 3 hours and 50 minutes to complete the primality test using LLR. Stephen is a member of the Clifford Welding Systems team.

The prime was verified on 30 December 2013 1:48:41 UTC, by [AF>France>Aquitaine>Cote-Adour-et-Gaves]Bernard 64250 of France using an Intel(R) Core(TM) i3-2330M CPU @ 2.20GHz with 4 GB RAM running Microsoft Windows 7 Home Premium. This computer took about 5 hours and 1 minute to complete the primality test using LLR. [AF>France>Aquitaine>Cote-Adour-et-Gaves]Bernard 64250 is a member of the L'Alliance Francophone team.

For more details, please see the official announcement.


15 Jan 2014 | 17:16:54 UTC · Comment


New TRP Mega Prime Found!
On 25 December 2013, 11:53:21 UTC, PrimeGrid’s The Riesel Problem project eliminated k=40597 by finding the mega prime:

40597*2^6808509-1

The prime is 2,049,571 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 22nd overall. This is the largest prime found in The Riesel Problem and PrimeGrid's 12th elimination. 52 k's now remain.

The discovery was made by Frank Meador (v149907) of the United States using an AuthenticAMD AMD Phenom(tm) 9500 Quad-Core Processor with 878 MB RAM running Linux. This computer took 29 hours 35 minutes to complete the primality test using LLR.

The prime was verified on 27 December 2013, 20:54:41 UTC, by Eliot Meadow of the United States using an Intel(R) Pentium(R) 4 CPU 2.80GHz with 2 GB RAM running Microsoft Windows XP Media Center. This computer took about 66 hours and 17 minutes to complete the primality test using LLR. Eliot is a member of the BOINCstats Team.


For more details, please see the official announcement.


15 Jan 2014 | 17:01:37 UTC · Comment


Fix for screen lag when running GPU
I'm putting this in the news/announcements because this may help people in many projects, not just PrimeGrid.

The downside to having an efficient GPU app is it's likely to produce a lot of screen lag. In some circumstances there's an easy fix that won't impact crunching speed.

If the lag is *only* happening in web browser windows, but not elsewhere, the problem is that the web browser is trying to use the GPU to speed up its screen rendering. That gets clobbered by the crunching happening on the GPU.

The browser should have a setting to enable or disable using the GPU, and it's enabled by default. Disabling GPU "acceleration" in the browser should completely eliminate the browser lag.

In Chrome, the setting is "Settings" -> "Show advanced settings" -> "Use hardware acceleration when available".

In Firefox, the setting is "Tools" -> "Options" -> "Advanced" -> "Use hardware acceleration when available".

It's likely a similar option exists in IE.
11 Jan 2014 | 18:24:20 UTC · Comment


Please update your Challenge selections!
We have had to modify the way you select CPU apps for the Year of the Horse -- Pony Express Challenge. The server was supposed to automatically choose the best (fasteft) of the three available CPU apps, but it wasn't.

You now must select the correct app manually. Please see this message for details.

I apologize for the inconvenience.
8 Jan 2014 | 17:55:47 UTC · Comment


Year of the Horse challenges start on January 3rd 2014, 18:00 UTC
With the start of the new year a new development in PrimeGrid challenges is about to take place. We will kick of of the 2014 challenge series with a dual challenge running on both the short (Pony Express edition) and the world record (Stallion Edition) Generalized Fermat Prime number search. Each will have their own scoreboard and you are free the participate in either or both of the challenges. Participants in the World Record category will however get 50% more challenge credit for the same position on the leaderboard.

The challenge will run for 15 days from January 3rd, 2014 18:00 UTC until January 18th, 2014, 18:00 UTC

For more information, assistance and cheery banter please do join us on the forums, either in the Stallion Edition thread or in the Pony Express Edition thread
30 Dec 2013 | 16:14:14 UTC · Comment


First base 5 mega prime found!
On 4 December 2013, 20:53:51 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=173198 by finding the mega prime:

173198*5^1457792-1

The prime is 1,018,959 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 67th overall. This is the first known base 5 mega prime. 88 k's now remain in the Riesel Base 5 Problem.

The discovery was made by Motohiro Ohno (syusui) of Japan using an Intel(R) Core(TM) i3-2120 CPU @ 3.30GHz with 4GB RAM running Microsoft Windows 7 Home Premium. This computer took about 22 hours and 29 minutes to complete the primality test using LLR. Motohiro is a member of the Team 2ch team.

The prime was verified on 6 December 2013 5:27:38 UTC, by Scott Brown (Scott Brown) of the United States using an Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz with 8 GB RAM running Microsoft Windows 7 Home Premium. This computer took about 33 hours and 22 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

For more details, please see the official announcement.
18 Dec 2013 | 3:53:50 UTC · Comment


Winter solstice challenge starts Dec 18 17:11 UTC
Dear all,

The end of the year is drawing closer and this is traditionally marked with the winter solstice challenge here at PrimeGrid. As in previous years we would like to invite everyone to join us in this celebration of tidings of comfort and joy by sieving away for the Proth Prime Search. The challenge will start on Dec 18 17:11 UTC and last for 72 hours.

For more information, cheery banter and general merrymaking please join us on the discussion board.

We hope to see you there and please do spread the word :)
10 Dec 2013 | 9:44:00 UTC · Comment


Upgrading to OS X 10.9 (Mavericks) NOT recommended due to broken CUDA support
If you are currently running any BOINC CUDA projects (not just PrimeGrid) on an Nvidia GPU we recommend that you do NOT UPGRADE to OS X 10.9 (Mavericks) at this time.

According to the BOINC Wiki, the Nvidia CUDA driver is broken. After ugrading to OS X 10.9, you will likely be unable to run any BOINC CUDA tasks until Nvidia fixes the driver.

There's an ongoing discussion located here.
4 Nov 2013 | 11:19:04 UTC · Comment


Leonids Challenge starts November 14th, 18:00 UTC
November traditionally sees the skies lit up with falling stars a couple of nights during the Leonids meteor shower. Similarly on here on PrimeGrid November is the time for a challenge on our 321 LLR sub-project. This year the challenge will take place between November 14th 18:00 UTC and November 19th 18:00 UTC.

We hope that many of you will join us in this challenge and as always you can visit our forum for more useful information, cheery banter and some free roaming cows, rats, dogs, pigs and just regular users.

Please do spread the word and invite anyone to join us.
1 Nov 2013 | 22:58:08 UTC · Comment


Factorial Prime Found!
On 30 August 2013, PrimeGrid’s PRPNet found the 2nd largest known Factorial prime:

147855!-1

The prime is 700,177 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 2nd for Factorial primes and 191st overall.

The discovery was made by Pietari Snow (Lumiukko) of Finland using an Intel(R) Core(TM) i7 CPU 940 @ 2.93GHz with 6 GB RAM running Linux. This computer took just a little over 69 hours and 37 minutes to complete the primality test using pfgw. Pietari is a member of the PrimeSearchTeam.

For more details, please see the official announcement.

17 Oct 2013 | 1:31:59 UTC · Comment


Another Record TRP Prime!
On 10 October 2013, 22:01:17 UTC, PrimeGrid’s The Riesel Problem project eliminated k=304207 by finding the mega prime:

304207*2^6643565-1

The prime is 1,999,918 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 23rd overall. This is the largest prime found in The Riesel Problem and PrimeGrid's 11th elimination. 53 k's now remain.

The discovery was made by Randy Ready (cncr04s) of the United States using an Intel(R) Xeon(R) CPU X5570 @ 2.93GHz with 24 GB RAM running Windows Server 2003. This computer took 37 hours 36 minutes to complete the primality test using LLR. Randy is a member of the Aggie the Pew team.

For more details, please see the official announcement.
15 Oct 2013 | 2:33:23 UTC · Comment


New TRP Sieve File: Action required if you use app_info.
With the discovery of a new TRP prime, we've released an updated TRP Sieve file. No action is necessary on your part UNLESS you use app_info.xml.

If you use app_info.xml, please read this thread for more information about the MANDATORY update.

Update: One day later and there's another world record TRP prime, and another new sieve file. If you're running app_info, you need to grab the latest sieve file once again. See the thread above for details.
10 Oct 2013 | 23:28:05 UTC · Comment


World Record TRP Prime!
On 5 October 2013, 19:06:07 UTC, PrimeGrid’s The Riesel Problem project eliminated k=398023 by finding the mega prime:

398023*2^6418059-1

The prime is 1,932,034 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 23rd overall. This is the largest prime found in The Riesel Problem and PrimeGrid's 10th elimination. 54 k's now remain.

The discovery was made by Vladimir Volynsky (Grey) of Russia using an Intel(R) Core(TM) i7- 3820 CPU @ 3.60GHz with 16 GB RAM running Windows 7 x64. This computer took 12 hours 43 minutes to complete the primality test using LLR. Vladimir is a member of the Russia team.

The prime was verified on 8 October 2013, 00:48:18 UTC, by Wolfgang Schwieger (DeleteNull) of Germany using an Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz with 16 GB RAM running Linux. This computer took 10 hours 4 minutes to complete the primality test using LLR. Wolfgang is a member of the Nemesis Germany team.

For more details, please see the official announcement.


10 Oct 2013 | 14:00:02 UTC · Comment


GFN APPapalooza!
We have a veritable smorgasbord of GFN apps available now:

CPU:

There are three CPU versions of Genefer available for the short GFN tasks. The SSE2 version is the slowest and is sent to 64 bit hosts that don't support SSE3. (Only very early Athlon-64s don't support SSE3).

The new SSE3 version of Genefer is about 20% faster and is automatically sent to CPUs that support SSE3 (that's most CPUs).

The AVX version of Genefer is about 50% faster than the SSE2 version and is automatically sent to Linux and Mac hosts with CPUs that support AVX, i.e., Sandy Bridge and later CPUs. The server can't detect whether a Windows host supports AVX, so to get the faster GeneferAVX app on Windows you must explicitly tell the server to send it by checking the "Force AVX" box on the PrimeGrid Prefences page.

The SSE3 discussion is here and AVX is here.

ATI/AMD GPUs:

At long last we have an operational OpenCL version of Genefer that run on ATI/AMD GPUs. Double precision floating point hardware is required on the GPU.

Discuss OpenCL here, and the discussion about compatible ATI/AMD GPUs is here.

Nvidia GPUs:

In addition to the CUDA app we've been using, the OpenCL app for ATI/AMD is also available for Nvidia. Use whichever one runs faster on your hardware. In general, it seems as if CUDA is faster on older, pre-Kepler GPUs (GTX 5xx and older), and OpenCL is faster on newer Kepler GPUs (GTX 6xx and newer.)

Discuss OpenCL here, and the discussion about compatible Nvidia GPUs is here.
13 Sep 2013 | 23:12:14 UTC · Comment


PrimeGrid is now on Rackspace!
We've just moved PrimeGrid to new servers provided by Rackspace. (Thank you, Rackspace!)

Discussion and details can be found in this thread.
25 Aug 2013 | 21:26:34 UTC · Comment


Fermat Divisor!
On 10 March 2013 17:07:02 UTC, PrimeGrid's Proth Prime Search project found a prime Fermat divisor:

183*2^1747660+1 Divides F(1747656)

The prime is 526,101 digits long and entered Chris Caldwell's The Largest Known Primes Database ranked 6th for prime Fermat divisors and 263rd overall.

The discovery was made by Bart van Rooijen of the Netherlands using LLR to complete the primality test. Bart van Rooijen is a member of the Dutch Power Cows team.

The prime was verified on 10 March 2013 by Aaron Everett of the United States using LLR to complete the primality test. Aaron Everett is a member of the Team USA team.

Due to a reporting error, the announcement of this find was missed back in March.

For more details, please see the official announcement.
1 Jul 2013 | 1:58:34 UTC · Comment


Fermat Divisor!
On 18 June 2013 16:51:36 UTC, PrimeGrid's Proth Prime Search project found a prime Fermat divisor:

2145*2^1099064+1 Divides F(1099061)

The prime is 330,855 digits long and entered Chris Caldwell's The Largest Known Primes Database ranked 10th for prime Fermat divisors and 2629th overall.

The discovery was made by Sai Yik Tang (tomakey) of Malaysia using an Intel(R) Core(TM) i5-2400 CPU @ 3.10GHz with 4GB RAM running Microsoft Windows 7 Enterprise. This computer took about 8 minutes to complete the primality test using LLR.

The prime was verified on 21 June 2013 1:43:48 UTC by Timothy Hitch (Tim) using an Intel(R) Core(TM)2 Duo CPU T8300 @ 2.40GHz with 4 GB RAM running Microsoft Windows 7 Ultimate. This computer took about 33 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
1 Jul 2013 | 1:54:47 UTC · Comment


Bonus Credit for Select Sub-Projects
In order to encourage greater participation in certain, less popular, sub-projects, we're experimenting with granting a credit bonus to select sub-projects.

Please see Bonus Credit Experiment for details.
25 Jun 2013 | 2:23:03 UTC · Comment


Wall-Sun-Sun Running Again!
Wall-Sun-Sun has been turned back on.

Please see this thread for more information.
18 Jun 2013 | 16:18:59 UTC · Comment


Long Duration SR5 Tasks May Be Prime
... so don't abort them!

If you notice that one of your SR5 tasks is running a LOT longer than usual, or even that it went back to 0% after reaching 100% done, DO NOT ABORT IT. You may have found a prime!

The test for base 5 Riesel numbers (i.e., of the form k*5^n-1) need to perform a second test if the first test indicates that the number may be prime, and the second test takes three times as long as the first test.

SR5 primes can be discussed here.
16 Jun 2013 | 18:53:57 UTC · Comment


PPS-Sieve OpenCL App for Mac/ATI Now Available
A long time ago in a gal..., er, well, in this galaxy, we used to be able to run the PPS-Sieve application on both Nvidia and ATI GPUs on Windows, Linux, and Mac OS.

Somewhere along the line the ATI app on Mac got broken and hasn't worked for a long time.

The app is once again working, so feel free to run PPS-Sieve on your ATI equipped Macs.

(For those who are interested, apparently what happened is that something like a year ago, I think something in Mac OS or the ATI drivers changed such that the Mac BOINC client couldn't detect that the drivers were present on the computer. As a result, it was telling the BOINC server that there were no drivers present, and the server therefore refused to send ATI apps to the client. The Mac BOINC client still isn't detecting the drivers, but I've modified the server to skip that check when the host computer is a Mac.)

To discuss this announcement, please go to this thread.
28 May 2013 | 0:39:19 UTC · Comment


World Record Fermat Divisor!
On 13 May 2013 12:41:57 UTC, PrimeGrid's Proth Prime Search project found a world record prime Fermat divisor:

57*2^2747499+1 Divides F(2747497)

The prime is 827,082 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 1st for prime Fermat divisors and 101st overall. Incidentally, it is also a new record for "weighted" prime Fermat divisors.

The discovery was made by Marshall Bishop (Wintermute) of the United States using an AMD Quad-Core AMD Opteron(tm) Processor 2374 HE with 32 GB RAM running Linux. This computer took about 2 hours 28 minutes to complete the primality test using LLR.

The prime was verified by [AF>Le_Pommier>MacGeneration.com] Sloughi of France using an Intel(R) Xeon(R) CPU E5645 @ 2.40GHz with 12 GB RAM running Mac OS X. This computer took about 4 hour and 46 minutes to complete the primality test using LLR. [AF>Le_Pommier>MacGeneration.com]Sloughi is a member of the L'Alliance Francophone team.

For more details, please see the official announcement.
25 May 2013 | 15:29:57 UTC · Comment


New Badges!
After much arm twisting, hair pulling, pixel-wrangling, and a lot of great discussion, PrimeGrid (with a LOT of help from many of our participants) has extended the range of badges that can be earned.

There's now 18 different badge levels for each project. Many people will see new badge colors and shapes. The old badges were easily exceeded; at least one person had in excess of 1000 times the credit needed for our highest badge. That's the case no longer; your mega-achievements will now be recognized!

The new badge levels can be seen here, and you can discuss the new badges here.

Happy crunching!
5 May 2013 | 13:12:33 UTC · Comment


Cheaters' credits rescinded
At the end of February, we discovered that a small group of people were cheating by faking results. Changes were immediately made to our validation software to prevent this from happening again.

We have rescinded all the credits from the users who were cheating. To be fair, we've also deducted those credits from the teams they were in. Of course, not everyone in their teams are cheaters, but fraudulently gained credits shouldn't count towards team scores. Some of the teams affected are amongst the oldest, largest teams here, and in some cases those teams have lost in excess of 1 billion credits.

The other team members, no doubt, knew nothing of the cheating, so no stigma should be attached to these teams, or their members. I'm listing the teams here only so that if you suddenly see your team's credits and/or rank have dropped, you'll know why.

The following teams (team ID: team name) have lost credits:

64: BOINC@Taiwan
1: BOINCstats
103: Dutch Power Cows
2887: TaiwanROC
852: SETI@Taiwan �x�W�&zeta;�
20 Apr 2013 | 20:50:31 UTC · Comment


Server Upgraded, GPU/CPU bug fixed
I just installed new BOINC server software. The primary feature of the new server is that this should permanently fix the problem of erroneously getting CPU apps when you request GPU apps.

New with this release of the the BOINC server:


  • CPU/GPU bug fixed.
  • New PPS-Sieve, GFN (short), and GFN (WR) plan-classes. As a result of the new plan-classes, all host computers running these projects will need to download these applications again. In most cases, it's the exact same software as before, only with different names.
  • Improved project selection:

    • You now select GFN and GFN-WR independently. This allows you to use different shift override values for long and short tasks, and lets you choose CPU and GPU independently.
    • If you select CPU tasks but have the "Use CPU" box unchecked, you get a warning that the tasks are disabled. The same applies to CUDA and ATI apps.
    • If you turn on "Use CPUs" but don't select any tasks, PPS-LLR is automatically selected for you. Likewise, if you select "Use CUDA" or "Use ATI" and don't select any CUDA or ATI apps (respectively), PPS-Sieve (CUDA or ATI) will be selected for you. This prevents a situation where your host would continuously try to get work without the server being able to deliver any work because nothing is selected.


  • New CUDA versions of GeneferCUDA have been installed for Windows and Linux. This is version 3.1.2-1 (2.05 in the BOINC numbering scheme), and improves CUDA error handling. The Mac version will be installed later when it becomes available.

16 Apr 2013 | 15:18:04 UTC · Comment


AVX enabled LLR apps now available on all 64 bit platforms
We just released the latest LLR 3.8.9 for all platforms. If you've been using app_info to enable use of AVX, you may not need to do so anymore.

Please see this post for more information.

Note: AVX support is not available for AMD Bulldozer CPUs.
21 Feb 2013 | 19:43:13 UTC · Comment


New LLR credit function
Your voices have been heard!

Well, we always heard you, but this wasn't the easiest thing to fix.

Anybody who has ever run any LLR project here probably noticed how seemingly random the credit was. Without going into detail, the variation was due to using the BOINC benchmark * CPU time method for calculating credit, which has lots of problems.

I've written a new credit function that is based soley on the complexity of the problem, so credit will be a lot more consistent than before.

We'll be turning the new credit system on one project at a time. You may notice that some projects will get more credit than before, and some may get less. The adjustment is to make it so that you get the same credit/hour regardless of which project you're crunching.

Currently, the new system is being used only for SGS. If nothing really bad happens, we'll start turning it on for the other projects. SGS used to have a fixed credit. It now varies slightly according to the size of the number. VERY slightly -- the difference is about 8 places past the decimal point, so you won't notice the difference, but it's there.

This should correct the following inequities with the old credit function:


  • Identical Windows and Linux boxes scored differently on the BOINC benchmarks, and therefore got different credit for the same amount of work.
  • Sandy and Ivy Bridge CPUs got LESS credit for being faster.
  • Your wingmen would affect your credit, so if THEY have a Sandy Bridge CPU, you get penalized because their computer is fast.
  • Hyperthreading and the effects of too-small CPU cache can cause crunching to slow down when all cores are in use, causing credit to go up because your computer is slower.

I'll keep you informed as the other projects are moved to the new system.

UPDATE: All LLR projects now use the new credit system.

EDIT: Added fourth bullet point about HT & cache misses causing higher credit as your computer slows down. 17 Feb 2013 | 20:59:09 UTC · Comment


Donation drive for the server move
As you all may know, our datacenter is closing down and we are moving the servers of PrimeGrid soon. We are taking the opportunity to move to the cloud, which will reduce our costs and will allow to purchase additional resources when needed (for example, during the challenges).

However, PrimeGrid does not have any financial backing from universities or organizations. For the last year we have not been receiving enough money from donations and Google ads. Therefore, we have over 800€ debt for the last year for collocation of the servers, and this year we have already added close to 300€. We also need the money for the purchase of new cloud services.

Because of this, we have to ask for your help. If you can help, please head to the donations page and make a contribution.

Each contribution, no matter how big or small, will earn you a donor's crown. However, we kindly ask you to keep the donation above 2€ because of transaction fees.

We have also added a direct transfer in the following countries: Austria, Belgium, Czech Republic, Estonia, Germany, Lithuania, Latvia, The Netherlands, Poland, Slovakia, United Kingdom. We now also accept WebMoney. These donation types will be handled by our new payment processor, mokejimai.lt.

One tiny note: because of the server move, all donations will be handled and entered into the database manually, therefore it may take some time until your donation is processed and appears in the donation page.

So, once again, if you can - please head to the donation page and make a contribution. It is you who helps keep PrimeGrid running! Thank you for your support in advance. And if you have any questions, do not hesitate to contact any of the staff.
5 Feb 2013 | 6:38:10 UTC · Comment


Upcoming PrimeGrid Down Time
The BOINC server move is ... COMPLETE!

(The PRPNet server has not yet moved.)

We moved PrimeGrid's BOINC system (www.primegrid.com) to a new server on Saturday, February 9th.

According to plan, the PRPNet server (prpnet.primegrid.com) was NOT moved on Saturday, so the PRPNet ports and web pages should were not affected. PRPNet will move at a later, as yet undetermined date. PRPNet ports that will be eventually be affected when the PRPNet server is moved are: GCW, Primorial, Factorial, GFN32768, GFN65536, 27, and 121.

The PrimeSearchTeam forums, used for manual sieving, are not affected and should remain up during the PRPNet move, as will the upload and download servers for manual sieving.

What should you do?

If you increased your cache size in preparation for the move, you can put it back to your regular settings.

In case the forums are down (this is NOT expected), you can use our chatroom at http://www.chatzy.com/46334617429062 to get updates or to communicate with us. The chatroom is an external site and won't be affected by the outage. You may wish to save or bookmark that URL.

When will this happen?

The web server, forums, and BOINC server were moved on Saturday, February 9th.

The PRPNet server will be moving at a later date sometime in February.

Does this affect the upcoming challenges?

Yes, it should ABSOLUTELY affect the Valentine's Day challenge! The new server appears to be significantly faster than the old server, so we're hoping for a nice, smooth challenge. We may need to tweak some tuning parameters, but so far we're very pleased with the performance on the new system.

We were down for a few hours, so that may have caused some difficulties for hosts trying to connect to get work for the Tour de Primes, but hopefully the affect was minimal.

The effect on the ongoing cleanup phase for the Year of the Snake challenge should be negligible.

Will PrimeGrid's URL or IP address change?

The URL did not change. The IP addresses DID change. The process of converting to the new IP should have been handled automatically by the DNS system and should require no action on your part, although it may take up to 24 hours for the mapping to propagate through the DNS servers. However, if for some reason you are using hard-coded IP address for PrimeGrid, you'll need to change them.

If your BOINC client is having trouble connecting to PrimeGrid, try rebooting your computer.
25 Jan 2013 | 14:30:23 UTC · Comment


PPS Mega Prime!
On 2 November 2012, 3:47:30 UTC, PrimeGrid’s Proth Prime Search project found the Mega Prime:

7*2^5775996+1

The prime is 1,738,749 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 24th overall.

The discovery was made by Martyn Elvy (Martyn Elvy) of New Zealand using an Intel(R) Xeon(R) CPU E5345 @ 2.33GHz with 3GB RAM, running Windows Server 2003. This computer took just over 11 hours 16 minutes to complete the primality test using LLR. Martyn is a member of the NZ.BOINC team.

The prime was verified by Robert Ruge (robert) of Australia using an Intel(R) Xeon(R) CPU X5650 @ 2.67GHz with 10 GB RAM, running Linux. This computer took just under 6 hours 24 minutes to complete the primality test using LLR.

For more details, please see the official announcement.
12 Nov 2012 | 3:43:05 UTC · Comment


PPS Mega Prime!
On 23 October 2012, PrimeGrid’s Proth Prime Search project found the Mega Prime:

9*2^3497442 +1

The prime is 1,052,836 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 51st overall. This prime is also a Generalized Fermat prime and ranks as the 12th largest found.

The discovery was made by Heinz Ming (parabol) of Switzerland using an Intel Core(TM) i7 CPU 860 @ 2.80GHz with 8GB RAM, running Windows 7 Professional. This computer took just over 5 hours 59 minutes to complete the primality test using LLR. Heinz Ming is a member of the Aggie The Pew team.

The prime was verified by Tim McArdle (Bauerwulf) of the United States using an AMD Athlon(tm) II P340 Dual-Core Processor with 6 GB RAM, running Windows 7 Professional. Jason is a member of the Don't Panic Labs team.

For more details, please see the official announcement.
6 Nov 2012 | 2:19:51 UTC · Comment


321 Blast Off Challenge! Reminder !!
Calling all crunchers! November 1st is drawing close, and on that day at 18:00 UTC PrimeGrid will launch into the 321 Blast Off Challenge on the 321 LLR subproject. We will be flying at top speed untill November 9th, 18:00 UTC by which time we hope to return safely to the ground with some magnificent results. Please feel free to join us by selecting the 321 LLR subproject on your accounts preference page. For more information and banter, join us on the forum!

And as always, please spread the word.
30 Oct 2012 | 12:46:15 UTC · Comment


321 Blast Off Challenge! on PrimeGrid
321 Blast Off Challenge!

Calling all crunchers! November 1st is drawing close, and on that day at 18:00 UTC PrimeGrid will launch into the 321 Blast Off Challenge on the 321 LLR subproject. We will be flying at top speed untill November 9th, 18:00 UTC by which time we hope to return safely to the ground with some magnificent results. Please feel free to join us by selecting the 321 LLR subproject on your accounts preference page. For more information and banter, join us on the forum!

And as always, please spread the word.
22 Oct 2012 | 3:32:39 UTC · Comment


An Apple a Day Challenge (Reminder)
Two days left to start !!

On October 5th at 18:00 UTC PrimeGrid's 2012 Challenge Series will see its next episode. The 'An Apple a Day' challenge is held on the Proth Prime Search (LLR) subproject and will last 24 hours. Work units will be very short, so every minute will count!

For more information please visit this topic on the forums.

Please spread the word on the challenge and hope to see you all on October 5th.
3 Oct 2012 | 11:56:11 UTC · Comment


An Apple a Day Challenge
On October 5th at 18:00 UTC PrimeGrid's 2012 Challenge Series will see its next episode. The 'An Apple a Day' challenge is held on the Proth Prime Search (LLR) subproject and will last 24 hours. Work units will be very short, so every minute will count!

For more information please visit this topic on the forums.

Please spread the word on the challenge and hope to see you all on October 5th.
11 Sep 2012 | 20:42:52 UTC · Comment


World Record GFN Prime!
On 8 Aug 2012, 8:58:58 UTC, PrimeGrid’s Generalized Fermat Prime Search found the largest known Generalized Fermat mega prime:
475856^524288+1

The prime is 2,976,633 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Generalized Fermat primes and 11th overall.

The discovery was made by Masashi Kumagai (ragnarag) of Japan using an NVIDIA GeForce GTS 450 in an AMD FX(tm)-8150 CPU with 8GB RAM, running 64 bit Windows 7. This GPU took 7 hours 47 minutes to probable prime (PRP) test with GeneferCUDA. Masashi Kumagai is a member of the Team 2ch team.

The prime was verified by Jason Preszler (Jason Preszler) of the United States using an Intel Core i7-2600 CPU @ 3.40GHz with 12GB RAM, running 64 bit LINUX . This computer took 46 hours 55 minutes to probable prime (PRP) test with GenefX64. Jason is a member of the Turan@BOINC team.

For more details, please see the official announcement.
21 Aug 2012 | 12:33:08 UTC · Comment


The Olympics Challenge
PrimeGrid's 2012 Challenge Series continues with the "Olympics Challenge".

PrimeGrid is offering 48 hr Challenge (3-5 Aug) on The Riesel Problem (Sieve) application. For more information, please see this forum post

p.s. Please spread the word about the Olympics Challenge.
31 Jul 2012 | 13:55:02 UTC · Comment


World Record GFN Prime!
On 20 Jun 2012, 4:26:47 UTC, PrimeGrid’s Generalized Fermat Prime Search found the largest known Generalized Fermat mega prime: 356926^524288+1

The prime is 2,911,151 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Generalized Fermat primes and 11th overall.

The discovery was made by (bherbihyewrbg) of Japan using an NVIDIA GeForce GT 640M in an Intel Core i7-3610QM CPU @ 2.30GHz with 8GB RAM, running 64 bit Windows 7 Professional. This GPU took 17 hours 49 minutes to probable prime (PRP) test with GeneferCUDA. (bherbihyewrbg) is a member of the Team 2ch team.

The prime was verified by Tim McArdle (Bauerwulf) of the United States using an Intel Core i7-2600 CPU @ 3.40GHz with 8GB RAM, running 64 bit Windows Server 2008 . This computer took 43 hours 46 minutes to probable prime (PRP) test with GenefX64. Tim is a member of the Don't Panic Labs team.

For more details, please see the official announcement.
25 Jul 2012 | 18:11:09 UTC · Comment


World Record GFN Prime!
On 15 Jun 2012, 9:27:36 UTC, PrimeGrid’s Generalized Fermat Prime Search found the largest known Generalized Fermat mega prime: 341112^524288+1

The prime is 2,900,832 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Generalized Fermat primes and 11th overall.

The discovery was made by Peyton Hayslette (Peyton Hayslette) of the United States using an NVIDIA GeForce GTX 560 Ti in an Intel Core i5-2500K @ 3.30GHz system with 16GB RAM, running 64 bit Windows 7 Ultimate. This GPU took 3 hours 48 minutes to probable prime (PRP) test with GeneferCUDA. Peyton is a member of the North Carolina team.

The prime was verified by Rob Bosma (Cow_tipping) of the Netherlands using an NVIDIA GeForce GTX 580 in an Intel Core i7 920 @ 2.67GHz with 16GB RAM, running 64 bit Windows 7 Ultimate. This GPU took 2 hours 26 minutes to probable prime (PRP) test with GeneferCUDA. Rob is a member of the Dutch Power Cows team.

For more details, please see the official announcement.

28 Jun 2012 | 15:03:23 UTC · Comment


GFN Sieving
There's an ongoing effort to finish up the GFN sieves. If you have Windows and a CUDA capable card, please consider participating in this manual sieve effort. See GFN Prime Search (GPU Sieving) for instructions. It's another good way to earn your PSA badge.

Wellcome

PrimeGrid/Admins
27 Jun 2012 | 18:00:32 UTC · Comment


A Request for Assistance
We are attempting to reach a BOINC user who found one of the recent GFN mega primes…ranked 11th in the World! We are seeking help from the BOINC community in finding this individual. (bherbihyewrbg) of Japan and Team 2ch

If you have contact with this individual, please have them check their BOINC emails or private messages in PrimeGrid's forum. Several attempts have already been made through these channels. Additionally, if you have any information that might help us in contacting this individual, please contact us here: http://www.primegrid.com/contact.php
25 Jun 2012 | 20:25:42 UTC · Comment


World Record TRP Prime!
On 23 June 2012, 7:58:18 UTC, PrimeGrid’s The Riesel Problem project eliminated k=252191 by finding the mega prime: 252191*2^5497878-1

The prime is 1,655,032 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 21st overall. This is the largest prime found in The Riesel Problem and PrimeGrid's 9th elimination. 55 k's now remain.

The discovery was made by Jan Haller (Janita) of Germany using an Intel Pentium Dual-Core E5400 @ 2.70GHz with 4 GB RAM running Windows 7. This computer took over 17 hours 30 minutes to complete the primality test using LLR.

The prime was verified on 23 June 2012, 15:35:21 UTC, by Tony Gott (bayanne) of the United Kingdom. Tony is a member of the Ars Technica team.

For more details, please see the official announcement.



25 Jun 2012 | 11:19:43 UTC · Comment


World Record GFN Prime Found...Twice!
Just prior to the start of the Alan Turing Year Challenge, not one, but two GFN mega primes were found! When all is finalized, these will be the 11th and 12th largest primes found to date and will be the two largest primes found by PrimeGrid. These are each incredible finds!

Internal verification of these primes is ongoing, and for primes of this size, will take a few days. Stay tuned for the official announcement.

There's still more than half of the challenge to go...Let's see if we can make it three (or more)! :)
22 Jun 2012 | 4:33:26 UTC · Comment


Prime Fermat Divisor Found
Congratulations to Robert Boniecki (Robert) of the United States, the discoverer of PrimeGrid's 12th Prime Fermat Divisor in the Proth Prime Search project: 1705*2^906110 + 1 Divides F(906108). This is the 298th known divisor and the 6th found in 2012 (4th by PrimeGrid). The prime is 272,770 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 9th for prime Fermat divisors and 2359th overall. Additionally, it ranks 1st in the Weighted Record Primes of this type at the Prime Pages.

For more details, please see the official announcement.


18 Jun 2012 | 11:48:01 UTC · Comment


Welcome to the Alan Turing Year Challenge
A 3 day Challenge is being offered on PrimeGrid's Generalized Fermat Number (GFN) application. Only SHORT Work Units may be used in this challenge. To participate in the Challenge, please select only the Generalized Fermat Prime Search project and also select Short tasks in your PrimeGrid preferences section. (The longer World Record GFN tasks can't be completed within the 3 day span of this challenge.) You may leave the Block Size setting at 0.

The challenge will begin 20 June 2012 23:09 UTC and end 23 June 2012 23:09 UTC.

IMPORTANT IMPORTANT !!

Read this post:http://www.primegrid.com/forum_thread.php?id=4411&nowrap=true#55369

Wellcome :)
17 Jun 2012 | 9:27:05 UTC · Comment


Prime Fermat Divisor Found
Congratulations to James Boerner (NullCoding*) of the United States, the discoverer of PrimeGrid's 11th Prime Fermat Divisor in the Proth Prime Search project: 7905*2^352281 +1 Divides F(352279). This is the 297th known divisor and the 5th found in 2012 (3rd by PrimeGrid). James is a member of the Sicituradastra. team.

For more details, please see the official announcement.
3 Jun 2012 | 13:03:55 UTC · Comment


The Cinco de Mayo Challenge. May 5 18:00 UTC
Come join us for the 5th day of the 5th month celebration. A 5 day Challenge is being offered on PrimeGrid's "The Riesel Problem" (LLR) application¦ends on the 10th. There remains 56 k's in The Riesel Problem for which no primes have been found.

For more information, please see this forum post.
2 May 2012 | 19:14:19 UTC · Comment


End-of-life for current iteration of Sophie Germain Prime Search
Because of the recent discovery and exhaustion of the search range, current iteration of Sophie Germain project is being finished. No new work will be inserted, and only some resends for unfinished work will be issued. There are plans to restart Sophie Germain search in the future: we are evaluating best approach to the problem at the moment.

If you have opted only into Sophie Germain project, we suggest revising your project preferences and selecting other projects so that you keep receiving work.
23 Apr 2012 | 18:19:01 UTC · Comment


Generalized Fermat Mega Prime
On 19 Apr 2012, 21:12:27 UTC, PrimeGrid’s Generalized Fermat Prime Search, through PRPNet, found the mega prime: 773620^262144+1

The prime is 1,543,643 digits long and enters Chris Caldwell's “The Largest Known Primes Database” ranked 2nd for Generalized Fermat primes and 22nd overall.

The discovery was made by Senji Yamashita of Japan using an NVIDIA GeForce GTX 580 in an Intel Core i7-970 @ 3.20GHz system with 6GB RAM, running Windows 7 Professional x64. This GPU took about 47 minutes to probable prime (PRP) test with GenefCUDA. Senji is a member of the PrimeSearchTeam.

For more details, please see the official announcement.
23 Apr 2012 | 1:10:46 UTC · Comment


World Record Sophie Germain prime found!
On 9 April 2012 6:31:14 UTC, PrimeGrid’s Sophie Germain Prime Search found a World Record Sophie Germain prime: 18543637900515*2^666667-1 (2p+1: 18543637900515*2^666668-1)

The prime is 200,701 digits long, eclipsing the previous record of 79,911 digits. It enters Chris Caldwell's “The Largest Known Primes Database” ranked 1st for Sophie Germain primes.

The discovery was made by Philipp Bliedung (pabliedung) of the United States using an Intel Core i7 950 @ 3.07GHz with 12 GB RAM running Linux. Philipp is a member of the USA team.

The prime was verified on 9 April 2012 9:36:15 UTC, by Lee Blyth (IshtarIS) of Australia using an Intel Core i7 2600k @ 3.40GHz with 8 GB RAM running Windows 7 Ultimate. Lee is a member of the Ishtar team.

For more details, please see the official announcement.
17 Apr 2012 | 1:36:06 UTC · Comment


March was a great month for the Extended Sierpinski Problem project
March was a special month for the Extended Sierpinski Problem (ESP) on PrimeGrid's PRPnet. After two years of crunching with no prime finds, two more k's were eliminated:

The first discovery was made by Timothy D. Winslow (Pooh Bear 27) of the United States on Wednesday 14th of March 2012. 123287*2^2538167+1 is prime and at 764070 digits entered Chris Caldwell's Top 5000 list as the 78th largest prime.

The second discovery was made by Rodger Ewing (Pilgrim) of the United States on Tuesday 27th of March 2012. 147559*2^2562218+1 is prime and at 771310 digits entered Chris Caldwell's Top 5000 list as the 77th largest prime.

15 k's now remain.

Congratulations to both Rodger and Tim! The next ESP find will very likely also be a Mega Prime!

For more information about the Extended Sierpinski Problem, see this forum post.
11 Apr 2012 | 21:09:00 UTC · Comment


The Marie Sophie Germain Challenge 2012 starts in 6 hr. :)
Marie-Sophie Germain was born on April 1, 1776, in Paris, France. She was an extraordinary "French mathematician who made important contributions to the fields of differential geometry and number theory and to the study of Fermat's Last Theorem." (Wiki) Come join us as we pay tribute to her with a 2 day (1-3 April) Challenge on the Sophie Germain Prime Search project.

For more information, please see this forum post.
1 Apr 2012 | 11:20:37 UTC · Comment


The Marie Sophie Germain Challenge 2012 starts in 3 days
Marie-Sophie Germain was born on April 1, 1776, in Paris, France. She was an extraordinary "French mathematician who made important contributions to the fields of differential geometry and number theory and to the study of Fermat's Last Theorem." (Wiki) Come join us as we pay tribute to her with a 2 day (1-3 April) Challenge on the Sophie Germain Prime Search project.

For more information, please see this forum post.
29 Mar 2012 | 13:29:45 UTC · Comment


The Marie Sophie Germain Challenge 2012
Marie-Sophie Germain was born on April 1, 1776, in Paris, France. She was an extraordinary "French mathematician who made important contributions to the fields of differential geometry and number theory and to the study of Fermat's Last Theorem." (Wiki) Come join us as we pay tribute to her with a 2 day (1-3 April) Challenge on the Sophie Germain Prime Search project.

For more information, please see this forum post.
19 Mar 2012 | 17:41:26 UTC · Comment


World Record Primorial prime
On 28 Feb 2012, PrimeGrid’s Primorial Prime Search, through PRPNet, has found a world record primorial prime: 1098133#-1

The prime is 476,311 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Primorial primes and 253rd overall.

The discovery was made by James P. Burt (jpaul) of the Cayman Islands using an AMD Phenom 9750 Quad-Core @ 2.4GHz with 4 GB RAM running Windows 7 Professional x64. James is a member of the Aggie_The_Pew team.

This is only the 20th known p#-1 Primorial prime and the 2nd discovered in the last 20 years. For more details, please see the official announcement.
2 Mar 2012 | 3:53:44 UTC · Comment


27 Mega Prime
On 28 Feb 2012, 15:51:22 UTC, PrimeGrid’s 27121 Prime Search, through PRPNet and in collaboration with the 12121 Search (k=27 sister project), has found the mega prime: 27*2^3855094-1

The prime is 1,160,501 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 34th overall. This is PrimeGrid's 23rd mega prime.

The discovery was made by Pietari Snow (Lumiukko) of Finland using an Intel Intel Xeon E5410 @ 2.33GHz with 12GB RAM, running Microsoft Windows Server 2003 64 bit. This computer took just over 4 hours 13 minutes to complete the primality test using LLR. Pietari is a member of the PrimeSearchTeam.

For more details, please see the official announcement.
28 Feb 2012 | 18:49:36 UTC · Comment


The Leap Day Challenge - "Just for Fun"
Four significant issues over the last six days in the run-up to the Leap Day Challenge has created so much havoc that it is prudent the Challenge be "changed". There are simply too many obstacles to overcome in such a short time span. Additionally, it is unknown when Nvidia will resolve the sleep issues related to the 295.73 driver.

The Leap Day Challenge will still be offered, stats will be provided, but only on a "Just for Fun" basis. For more details about the issues and the effect this will have on the annual Challenge Series, please see this post.
28 Feb 2012 | 4:50:09 UTC · Comment


Nvidia Windows driver 295.xx/296.xx problems
We are seeing an elevated error rate from hosts using Nvidia drivers 295.xx.

If your monitor is put to sleep by the computer, the GPU is no longer available as a CUDA device. This will cause an immediate failure of any CUDA WUs. This includes GFN/Genefer, PPS Sieve, GCW Sieve, and llrCUDA.

In the mean time we can only suggest not to upgrade to this version (or downgrade if already installed), or disable power saving in the system.

We will update once we have more information.
27 Feb 2012 | 7:06:56 UTC · Comment


The Leap Day Challenge in 3 days
Leap Day 2012 is just 3 days away. While you are off enjoying your extra day, having a good time, your computer sits at home envious. Why not give it something fun to do as well? Come join the Leap Day Challenge, a 24 hour Challenge offered on PrimeGrid's Cullen/Woodall (Sieve) application.

For more information, please see this forum thread.
26 Feb 2012 | 20:18:36 UTC · Comment


121 Mega Prime
k=121 has finally opened its vault. After 6 years of stubbornness, it relinquishes its strong hold on primes. On 25 Feb 2012, 06:34:08 UTC, PrimeGrid’s 27121 Prime Search, through PRPNet and in collaboration with the 12121 Search, has found the mega prime: 121*2^4553899-1

The prime is 1,370,863 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 28th overall. This is PrimeGrid's 22nd mega prime.

The discovery was made by Timothy D. Winslow (Pooh Bear 27) of the United States using an Intel Intel i7 930 @ 2.8GHz with 12GB RAM, running Microsoft Windows 7 Home Premium 64 bit. This computer took just over 5 hours 49 minutes to complete the primality test using LLR. Timothy is a member of the The Knights Who Say Ni! Team.

For more details, please see the official announcement.
26 Feb 2012 | 16:47:36 UTC · Comment


The Leap Day Challenge in 7 days
What to do with an EXTRA day in the year??? One could take a nap, read a book, go skiing/walking/hiking/swimming/etc, spend time with family, watch your favorite movie...and the list goes on and on. :) However, what your computer can do with an extra day is easy...come join the Leap Day Challenge, a 24 hour Challenge offered on PrimeGrid's Cullen/Woodall (Sieve) application.

For more information, please see this forum thread.
22 Feb 2012 | 18:46:13 UTC · Comment


Tour de Primes 2012 - Mountain Stage
The mountain stage is finally upon us. The coveted polka-doted jersey will go to the participant who finds the most primes between 19 Feb 2012 00:00 UTC and 20 Feb 2012 00:00 UTC. In case of a tie, the combined prime score will determine the winner. For more information about the tour, please see Tour de Primes 2012

UPDATE: Mountain stage extended to 48 hours to accommodate a policy update. Runs between 19 Feb 2012 00:00 UTC and 21 Feb 2012 00:00 UTC.

Best of Luck to everyone!
18 Feb 2012 | 13:24:40 UTC · Comment


February's PRPNet Challenge Project
The Wieferich Prime Search is PrimeGrid's PRPNet Challenge project for February...dubbed the "Wild Whacky Whimsical Wednesday" (WWWW) Challenge. This is the 2nd Challenge in the 2012 PRPNet Challenge Series.

The 24 hour Challenge will run from 15 February 2012 00:00 UTC to 16 February 2012 00:00 UTC. This is for those users who wish for a bit more variety in their prime search endeavors and don't mind venturing outside of BOINC to PRPNet. :) It's a relaxed and informal environment so stop by and see what you think.

For more information, please see this thread.
14 Feb 2012 | 19:06:24 UTC · Comment


Generalized Fermat Mega Prime
On 12 Feb 2012, 3:48:23 UTC, PrimeGrid’s Generalized Fermat Prime Search found the mega prime: 676754^262144+1

The prime is 1,528,413 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 2nd for Generalized Fermat Primes and 23rd overall. This is the 2nd Top 25 prime in 3 weeks. A nice beginning for the new Generalized Fermat Prime Search. The primes are only going to get bigger. :)

The discovery was made by Carlos Loureiro (Usucapio Libertatis) of Portugal using an NVIDIA GeForce GTX 550 Ti in an Intel Core i5-2500K @ 3.30GHz system with 4GB RAM, running Windows 7 Ultimate x64. This GPU took about 1 hour 30 minutes to probable prime (PRP) test with GenefCUDA. Carlos is a member of the Blasfemias team.

The PRP was verified on 12 Feb 2012, 8:33:09 UTC, by Peter Verstappen (verstapp) of Australia. For more details, please see the official announcement.
13 Feb 2012 | 15:23:32 UTC · Comment


Prime Fermat Divisor Found
Congratulations to Rob Derrera (TEAM BIGDOG) of the United States, the discoverer of PrimeGrid's 10th Prime Fermat Divisor in the Proth Prime Search project: 131*2^1494099+1 Divides F(1494096). This is the 294th known divisor and the 2nd found in 2012. Rob is a member of the US Navy team.

For more details, please see the official announcement.
7 Feb 2012 | 15:02:45 UTC · Comment


Generalized Fermat Prime Search
The Generalized Fermat Prime Search is now out of beta and open to all users. An Nvidia GPU with double precision floating point hardware is required for this project. Also, MacIntel CPU's are supported at the current N=262144 (b^2^18).

A wealth of discussion has been gathered during the beta phase. For any issues or questions, please see the Generalized Fermat Prime Search forum.

This search will eventually reach N=4194304 (b^2^22) which, if successful, has the potential of discovering the world's largest known prime number. Current testing times at N=262144 are ~1 hr for fast GPU's and ~7 hrs for fast MacIntel CPU's.

Best of Luck to everyone!
4 Feb 2012 | 18:38:49 UTC · Comment


Call for arms: full doublecheck of TRP
We have recently started a limited doublecheck effort for The Riesel Problem and this has very quickly yielded a prime, which means that the results that we obtained from Riesel Sieve project cannot be trusted 100%. Therefore we have decided to run a full doublecheck effort.

We would like to quickly go through the doublecheck ranges and resume our original search, so we would like to ask you to consider redirecting any resources you may have available to The Riesel Problem (TRP) subproject. You can do that by visiting project preferences page.

Applications are available for Windows, Linux and Mac. 32bit applications will be sent to 64bit hosts.
3 Feb 2012 | 12:22:23 UTC · Comment


Prime found for the Riesel Problem
On 2 Feb 2012, 21:30:55 UTC, PrimeGrid’s The Riesel Problem project eliminated k=162941 by finding the prime: 162941*2^993718-1

The prime is 299,145 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 1536th overall. This prime was found while exploring a suspected gap in a previously searched range. This is PrimeGrid's 8th elimination. 56 k's now remain.

The discovery was made by Dmitry Domanov (unconnected) of Russia using an Intel Xeon @ 3.60GHz with 2 GB RAM running Windows Server 2003 Enterprise x86. This computer took just over 1 hour 5 minutes to complete the primality test using LLR. Dmitry is a member of Team Russia.

For more details, please see the official announcement.
3 Feb 2012 | 5:02:47 UTC · Comment


The Tour de Primes Begins!
Come join us in laid-back competition in tribute to the number 2...the first prime and the only even prime. The prizes are simple colored jerseys . Yellow for the most primes, Green for the highest prime score, and Polk-a-dot for the most primes on 19 Feb. No pressure or stress other than what you put on yourself. :) For more information, please see Tour de Primes 2012. 1 Feb 2012 | 0:29:32 UTC · Comment


World Record Generalized Cullen Prime
On 29 Jan 2012, 08:10:03 UTC, PrimeGrid’s PRPNet found the largest known generalized Cullen prime: 427194*113^427194+1

The prime is 877,069 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for generalized Cullen primes and 57th overall.

The discovery was made by Ricky L. Hubbard (MiHost) of the United States using an AMD Phenom II X6 1090t @ 3.2GHz with 8GB RAM, running Windows 7. This computer took 7 hours and 15 minutes to complete the probable prime test using pfgw64 and 7 hours 20 minutes to complete the primality test again using pfgw64. Ricky is a member of the AMD Users Team.

For more details, please see the official announcement.
30 Jan 2012 | 2:12:11 UTC · Comment


Tour de Primes 2012
February is just a week away which means it is time for the 4th annual Tour de Primes. 2 is the first prime number...and the only even one. Therefore, we have declared February, the 2nd month, as prime month.

We're offering a small informal competition in tribute to this unique prime number. There are no points to be gained or awards to be won...just a simple rare jersey (Yellow, Green, and Polk-a-dot) at the end of the month to add to your badge collection. No pressure or stress other than what you put on yourself. :) For more information, please see Tour de Primes 2012.
24 Jan 2012 | 16:23:12 UTC · Comment


The Year of the Dragon in 24 hours
The Dragon, the mightiest of all the signs, is a creature of myth and legend. In Asia, the Dragon is an auspicious creature, a symbol of benevolent power, strength and good luck and capable of great good. 23 January 2012 marks the start of the Year of the Dragon. Let's see if we can channel that Dragon energy to find some primes for the start of PrimeGrid's 2012 Challenge Series.

A 5 day Challenge is being offered on PrimeGrid's Proth Prime Search (LLR) application. For more information, please see this forum thread.
22 Jan 2012 | 15:22:23 UTC · Comment


Generalized Fermat Mega Prime
On 18 Jan 2012 21:13:24 UTC, PrimeGrid’s Generalized Fermat Prime Search found the mega prime: 525094^262144+1

The prime is 1,499,526 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 2nd for Generalized Fermat Primes and 24th overall.

The discovery was made by David Tomecko (KWSN Raw Data) of the United States using an NVIDIA GeForce GTX 570 in an Intel Core i7 980 @ 3.33GHz system with 24GB RAM, running Windows 7 Ultimate. This GPU took about 55 minutes 24 seconds to probable prime (PRP) test with GenefCUDA. David is a member of the The Knights Who Say Ni! team.

The PRP was verified on 19 Jan 2012 7:37:53 UTC, by Rick Reynolds (Rick Reynolds) of the United States. For more details, please see the official announcement.
22 Jan 2012 | 3:48:31 UTC · Comment


Mega Prime Found
On 17 Jan 2012 20:24:07 UTC, PrimeGrid’s Mega Prime Search, through PRPNet, found the Mega Prime: 81*2^3352924+1

The prime is 1,009,333 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 42nd overall. This prime is also a Generalized Fermat prime and ranks as the 6th largest found.

The discovery was made by Michał Gasewicz (Genn) of Poland using an Intel dual Xeon E5520 @ 2.27GHz with 12GB RAM, running 64 bit Linux. This computer took just over 4 hours 28 minutes to complete the primality test using LLR. Michał is a member of the BOINC@Poland team.

For more details, please see the official announcement.
18 Jan 2012 | 15:35:16 UTC · Comment


AVX build of llr
Gary Craig, a member of Aggie The Pew, was successful in compiling an AVX version of LLR using gwnum v27.2 and LLR v3.8.6dev. We've been testing it for the past week with success. Depending on the LLR project, speed improvements range from 20% to 50%.

For more details, please see this post
9 Jan 2012 | 6:35:17 UTC · Comment


Prime Fermat Divisor Found
Congratulations to Bruce Dodson (bdodson*) of the United States, the discoverer of PrimeGrid's 9th Prime Fermat Divisor in the Proth Prime Search project: 329*2^1246017+1 Divides F(1246013). This is the 293rd known divisor and the 1st found in 2012. Bruce is a member of the Sicituradastra. team.

For more details, please see the official announcement.
6 Jan 2012 | 22:46:22 UTC · Comment


Welcome to 2012
The New Year is here and so to are a couple of new projects at PrimeGrid. The Wieferich and Wall-Sun-Sun prime searches are now available through PrimeGrid's PSA PRPNet. Already in beta testing, a new "near" Wieferich prime (|A| < = 100) has been found. [correction - the "near" Wieferich prime was already known]

This first week of 2012 is planned as a home warming party. Please stop by, crunch a few WU's and read up more about these extremely rare and unique primes. For more information, please see A week of Wieferich and Wall-Sun-Sun.
1 Jan 2012 | 0:07:41 UTC · Comment


2011 Challenge Series Final Rankings
PrimeGrid's 2011 Challenge Series is final. Another incredible year of growth and competition...so much so that the servers were stressed again on a few Challenges. A tremendous about of work was accomplished leading to some pretty special primes found this year.

Congratulations to Sicituradastra. as the top team and Snf* as the top individual. They are the winners of PrimeGrid's 2011 Challenge Series. For complete, extended rankings please see: Individuals | Teams

As always, thank you for your help and support. We continue to be humbled by your participation. None of this is possible without YOU! :) Have a safe and happy Holiday season. See you next year for PrimeGrid's 2012 Challenge Series!
31 Dec 2011 | 3:59:08 UTC · Comment


World Record Twin Primes
On 25 Dec 2011 13:31:28 UTC, PrimeGrid's Sophie Germain Prime Search found World Record Twin Primes: 3756801695685*2^666669±1

The twin primes are 200,700 digits long, eclipsing the previous record of 100,355 digits. They will enter Chris Caldwell's The Largest Known Primes Database ranked 1st for twins. This is PrimeGrid's third record twin.

The discovery was made by Timothy D. Winslow of the United States using an Intel Core i7 920 @ 2.67GHz with 8 GB RAM running Windows 7 Ultimate. This computer, using LLR, took 9 minutes and 21 seconds to complete the primality tests of both primes. Timothy is a member of The Knights Who Say Ni! team.

The prime was verified on 26 Dec 2011 1:58:19 UTC, by Brage E. Elliott of the United States. For more details, please see the official announcement.
26 Dec 2011 | 6:53:27 UTC · Comment


World Record Twin Primes Found!
It appears that one lucky cruncher has received a very nice Christmas gift. Twin primes have been returned to the server and verified. They were found in the Sophie Germain Prime Search and are almost twice the size of the current record. This is an incredible accomplishment!

We are awaiting contact from the appropriate users. Stay tuned for more details. :)
26 Dec 2011 | 5:21:24 UTC · Comment


The Winter Solstice Challenge - Final
The Winter Solstice is here!!! The yule log, filled with factors, is making for a very bright night. This has been a very successful Challenge not only for PrimeGrid but also for the entire Riesel prime search community (benefactors of the k*2^n-1 that's also sieved). Once again, a new single day record was set during the final Challenge of the year. A hearty thanks and a warm appreciation for all those involved.

Over 2.86P of sieve work was crunched in ~318K tasks resulting in just over 1B cobblestones awarded. This is again a continuing legacy for Ken Brazier's tpsieve* port to the GPU. (*originally developed by Geoff Reynolds in collaboration with Ken Brazier)

Congratulations to Sicituradastra. as the top team and STE\/E as the top individual. For more stats and information, please see this forum post.

This concludes PrimeGrid's 2011 Challenge Series. Overall final results will be posted in a couple of days. Thank you to everyone who participated this year. We wish you a Happy Holidays and hope to see you next year!
22 Dec 2011 | 6:15:18 UTC · Comment


The Winter Solstice Challenge - 12 hrs remaining
The Solstice is soon upon us. Bundle up tight as it's going to be a long Winter's night. 12 hours remain in the Challenge. Time to round up all those factors, combine them into one HUGE yule log, and toss it into the fire.

The Winter Solstice arrives at 05:30 UTC 22 December 2011. Get your factors in by then. :)
21 Dec 2011 | 17:31:31 UTC · Comment


The Winter Solstice Challenge in 24 hours
The Solstice draws near and so does the start of the Winter Festival. Come one, come all and warm yourselves by the Solstice fires. PrimeGrid's 2011 Challenge series ends with a 3 day (19-22 Dec) Challenge on the PPS (Sieve) application.

For more information, please see this forum thread.
18 Dec 2011 | 5:27:19 UTC · Comment


The Winter Solstice Challenge in 3 days
The Solstice fires are currently being constructed. Foraging through the DB, we're gathering all the "cast off" factors and adding them to the stack. Come join the winter festival on the 19th as we celebrate the upcoming Solstice. Find your own factors and toss them into the fire.

A 3 day (19-22 Dec) Challenge is being offered on the PPS (Sieve) application. For more information, please see this forum thread.
16 Dec 2011 | 17:04:10 UTC · Comment


The Winter Solstice Challenge in 6 days
For those of us in the Northern Hemisphere, the full force of Winter is soon here. Please come join us in observing one of Nature's way-points...the Winter Solstice. A 3 day (19-22 Dec) Winter Festival/Challenge is being offered on the PPS (Sieve) application. 32 & 64 bit builds are available for Mac, Linux, and Windows as well as CUDA/ATI (OpenCL) for the GPU.

This will conclude PrimeGrid's 2011 Challenge series. For more information, please see this forum thread.
13 Dec 2011 | 1:22:12 UTC · Comment


GFN Prime Search Sieving
It has been a lukewarm response to the re-start of GFN sieving. This sieve will support 3 new N's in the GFN prime search (1048576, 2097152, 4194304). If you have Windows 64 bit and would like to put it to good use in a specialized sieve (one of which might eventually produce the world's largest prime), then please review these instructions.

This manual sieve is located in the Project Staging Area. It's a simple and straight forward process. For more details, please see this post.
7 Dec 2011 | 3:50:11 UTC · Comment


The March to the Solstice
Come join the March to the Solstice (24 Nov - 19 Dec). We'll be pushing PPS (LLR) as far along as possible before the final Challenge of the year, the Winter Solstice Challenge (19 Dec - 22 Dec). We have established intermediate goals for PPS (LLR) and are within striking distance of completing them by the end of year 2011.

This by no means is a "walk in the park". :) It will take a concentrated and sustained effort to reach these goals. For more details, please see this post.
28 Nov 2011 | 4:08:20 UTC · Comment


World Record Generalized Fermat Prime
On 19 Nov 2011 14:03:58, PrimeGrid's PRPNet found the largest known Generalized Fermat mega prime: 75898^524288+1

The prime is 2,558,647 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Generalized Fermat Primes and 13th overall. This is the first prime found at N=524288.

The discovery was made by Michael Goetz of the United States using an NVIDIA GeForce GTX 460 in an Intel Core2 Q6600 @ 2.4GHz system with 8GB RAM, running 64 bit Windows 7. The GPU took just under 5 hours to probable prime (PRP) test with GeneferCUDA. The CPU completed the primality test using pfgw64 in a little over 8 days! Michael is a member of the SETI.USA team.

For more details, please see the official announcement.
19 Nov 2011 | 21:41:43 UTC · Comment


The Leonids Challenge in 24 hours
Come see if you can catch a "falling star" in the Leonids meteor shower Challenge. A 5 day Challenge is being offered on the 321 Prime Search (LLR) project. For more information, please see this forum post. 17 Nov 2011 | 18:45:14 UTC · Comment


The Leonids Challenge in 3 days
In 3 days, the Leonids Challenge will begin. Come watch the "falling stars" and see if you can snag a 321 Mega Prime. A 5 day (18-23 November) Challenge is being offered on the 321 Prime Search (LLR) application. For more information, please see this forum post. 15 Nov 2011 | 21:01:50 UTC · Comment


The Leonids Challenge in 5 days
In 5 days, the Leonids Challenge will begin. Come watch the "falling stars" and hopefully find a rare 321 prime. A 5 day (18-23 November) Challenge is being offered on 321 Prime Search (LLR) application. For more information, please see this forum post. 13 Nov 2011 | 6:57:45 UTC · Comment


LLR v3.8.6 released
After experiencing some erratic behavior from several new hosts, specifically the AMD FX(tm)-8120 Eight-Core Processor, we have updated LLR from v3.8.4 to v3.8.6. This latest version uses GWNUM v26.6, and it appears to have solved the problem.

We expect high bandwidth usage over the next several hours as LLR v3.8.6 is downloaded for Linux, Windows, and Mac OS's.
11 Nov 2011 | 19:19:58 UTC · Comment


World Record Generalized Fermat Prime
On 29 Oct 2011 11:31:47 UTC, PrimeGrid’s PRPNet found the largest known Generalized Fermat Prime: 361658^262144+1

The mega prime is 1,457,075 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Generalized Fermat Primes and 24th overall.

The discovery was made by Michel Johnson of Germany using an NVIDIA GeForce GTX 550 Ti in an AMD PHENOM II X6 1100T @ 3.3GHz system with 4GB RAM, running 32 bit Windows XP. This GPU took about 1 hour and 45 minutes to probable prime (PRP) test with GenefCUDA. (NOTE: This is the first prime found by geneferCUDA!) Michel is a member of the SETI.Germany team.

The prime was confirmed in 50 hours and 40 minutes using pfgw64 on an Intel Xeon 5410 @ 2.33GHz with 16GB RAM, running Windows Server 2003 x64.

For more details, please see the official announcement.
6 Nov 2011 | 13:55:55 UTC · Comment


SGS single primes reaching the end of the Top 5000 list
The single primes as a byproduct from the Sophie Germain Prime Search are reaching the end of their stay in the Top 5000 list. There's roughly 10-14 days left until they will no longer enter the list. This does not affect the overall search as the goal remains to find a Sophie Germain prime and/or a twin prime.

If you're still looking for your first reportable SGS single prime, now's the time to get it. The elusive Sophie Germain and twin primes are still at large so there remains a chance at finding one of them as well. :)

To run this project, simply select "Sophie Germain Prime Search (LLR)" on your PrimeGrid preferences page.
20 Oct 2011 | 15:14:03 UTC · Comment


October's PRPNet Project
The dual Sierpinski problem (Five or Bust) is PrimeGrid's PRPNet project of the month for October. The goal will be to complete the double check effort before the end of the month.

The project will run from 1 October to 31 October (hopefully it will end sooner). It will be a great opportunity to be part of worthy cause in closing out the dual Sierpinski problem. Feel free to stop by after the Equinox Challenge is complete. For more information, please see this forum post.
1 Oct 2011 | 3:19:00 UTC · Comment


The Equinox Challenge Update
Just over a week into the 13 day Equinox Challenge and the competition is heating up. A lot of back and forth going on by both teams and individuals in some very tight races. It's not too late to get another couple of WU's completed before the end (06 Oct 2011 18:00 UTC). Sadly, no luck with finding a Woodall prime yet.

For more information on joining the Challenge, please see this forum post.
1 Oct 2011 | 3:04:36 UTC · Comment


The Equinox Challenge in 22 hours
A 13 day Challenge marathon on the Woodall Prime Search project approaches in just 22 hours. This Challenge is PrimeGrid's longest of the year and the Challenge points the highest. Come join us on the autumnal equinox, 23 Sep 2011 18:00 UTC, and see how many tasks you can return by 06 Oct 2011 18:00 UTC.

For more information, please see this forum post.
22 Sep 2011 | 20:05:40 UTC · Comment


The Equinox Challenge in 5 days
PrimeGrid's Challenge series continues with the "Equinox Challenge". Come join us as we usher in the fall and cooler temperatures with a 13 day marathon on the Woodall Prime Search project. The challenge will begin on the autumnal equinox, 23 Sep 2011 18:00 UTC, and end 06 Oct 2011 18:00 UTC.

For more information, please see this forum post.
19 Sep 2011 | 2:46:24 UTC · Comment


Prime Fermat Divisor found
Congratulations to Grzegorz Granowski (Grzegorz Granowski) of Poland, the discoverer of PrimeGrid's 8th Prime Fermat Divisor in the Proth Prime Search project: 25*2^2141884+1 Divides F(2141872). This is the 292nd known divisor and the 9th found in 2011. Grzegorz is a member of the Polish National Team.

For more details, please see the official announcement.
12 Sep 2011 | 14:27:01 UTC · Comment


PRPnet issues
Because of a router failure some PRPnet servers for Project Staging Area are not accessible. None of the BOINC services are affected and all are running fine.

We are trying to work around the problem by routing network requests around because the hardware isn't accessible at the moment and can't be rebooted and/or replaced. Because of this you may see some connection errors in the nearest future.

Update 19:10: PRPnet requests are now being routed around the failed router. PRPnet IP address has changed, so it will take time for DNS to synchronize - if you still can't connect, please give it some more time.
24 Aug 2011 | 17:43:16 UTC · Comment


The Dog Days of Summer Challenge
The Dog Days are here! In just 6 days, PrimeGrid's Challenge series continues with the Dog Days of Summer Challenge (26-28 August). Please come join us for a 2 day Challenge on PrimeGrid's Proth Prime Search (LLR) application. Builds are available for Linux, Mac and Windows.

For more information, please see this forum thread.
20 Aug 2011 | 22:41:50 UTC · Comment


Prime Fermat Divisor found
Congratulations to Peter Doggart (Hammeh) of the United Kingdom, the discoverer of PrimeGrid's 7th Prime Fermat Divisor in the Proth Prime Search project: 4479*2^226618+1 Divides F(226614). This is the 291st known divisor and the 8th found in 2011. Peter is a member of PrimeSearchTeam.

For more details, please see the official announcement.
10 Jul 2011 | 4:59:18 UTC · Comment


Prime Fermat Divisor found
Congratulations to Mark Doom (Mark Doom) of the United States, the discoverer of PrimeGrid's sixth Prime Fermat Divisor in the Proth Prime Search project: 3771*2^221676+1 Divides F(221670). This is the 289th known divisor and the 6th found in 2011. Mark is a member of team Aggie The Pew.

For more details, please see the official announcement.
2 Jul 2011 | 16:09:28 UTC · Comment


Prime Fermat Divisor found
Congratulations to Dirk D'huyvetters (Dirk) of Belgium, the discoverer of PrimeGrid's fifth Prime Fermat Divisor in the Proth Prime Search project: 7333*2^138560+1 Divides F(138557). This is the 288th known divisor and the 5th found in 2011.

For more details, please see the official announcement.
23 Jun 2011 | 19:26:17 UTC · Comment


World Record Prime Fermat Divisor
Congratulations to Scott Brown (Scott Brown) of the United States, the discoverer of a World Record Prime Fermat Divisor: 9*2^2543551+1 Divides F(2543548).

The prime is 765,687 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Prime Fermat Divisors and 57th overall.

This is PrimeGrid's 1st found prime Fermat divisor since 2009 and 4th overall. This is the 287th known divisor and the 4th found in 2011.

For more details, please see the official announcement.
23 Jun 2011 | 3:09:01 UTC · Comment


PrimeGrid's Birthday/Summer Solstice Challenge - Final
The Summer Solstice has arrived in the Northern Hemisphere. We hope everyone enjoys this longest day of the year...and for you Southern Hemisphere folks, we hope you kept warm. :)

The Cullen/Woodall (Sieve) reached an incomplete depth of over 566T. Over 30T of sieve work was crunched in 251K tasks resulting in over 91.5M cobblestones awarded.

Congratulations to Sicituradastra. as the top team and Ross* as the top individual. For more stats and information, please see this forum post.

Thank you again to everyone. We appreciate your participation and hope you had fun! Have a wonderful summer and we look forward to seeing you in a couple months at the next Challenge - The Dog Days of Summer Challenge - 26-28 August - 48 hours on the PPS (LLR) application! Come take a break from the Dog Days and cool off with a few primes. It's a GREAT opportunity for you to find a Top 5000 Prime. :)
21 Jun 2011 | 17:57:11 UTC · Comment


PrimeGrid's Birthday/Summer Solstice Challenge in 2 days
PrimeGrid's Challenge series continues with the "Birthday/Summer Solstice Challenge". Come join us as we celebrate PrimeGrid's 6th birthday. A 24 hour Challenge is being offered on the Cullen/Woodall (Sieve) application. The celebration will culminate in the ancient observation of the Summer Solstice, 21 June!

For more information, please see this forum post.
18 Jun 2011 | 1:08:46 UTC · Comment


World Record Factorial Prime
On 11 June 2011, PrimeGrid’s PRPNet found the largest known Factorial prime: 110059!+1

The prime is 507,082 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Factorial primes and 130th overall.

The discovery was made by Peter Doggart (Hammeh) of the United Kingdom using an AMD Phenom 9600 X4 @ 2.3GHz with 3GB RAM, running 32 bit Windows 7. This computer took just under 57 hours and 46 minutes to complete the primality test using pfgw. Peter is a member of the PrimeSearchTeam.

For more details, please see the official announcement.
13 Jun 2011 | 3:03:18 UTC · Comment


Mega Prime found for The Riesel Problem (Déjà vu Déjà vu)
On 31 May 2011 20:08:26 UTC, PrimeGrid’s The Riesel Problem project eliminated k=353159 by finding the mega prime: 353159*2^4331116-1

The prime is 1,303,802 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 25th overall. This is the largest prime found in The Riesel Problem and PrimeGrid's 7th elimination. 57 k's now remain.

The discovery was made by Jaakko Reinman (sqweeser) of Finland using an Intel Core2 Quad Q9550 @ 2.83GHz with 4 GB RAM running Linux. This computer took just over 8 hours and 9 minutes to complete the primality test using LLR. Jaakko is a member of the BOINC@Finland team.

The prime was verified on 1 Jun 2011 4:05:40 UTC, by Grzegorz Granowski (Grzegorz Granowski) of Poland. For more details, please see the official announcement.
1 Jun 2011 | 13:16:25 UTC · Comment


Mega Prime found for The Riesel Problem
On 26 May 2011 11:08:52 UTC, PrimeGrid’s The Riesel Problem project eliminated k=141941 by finding the mega prime: 141941*2^4299438-1

The prime is 1,294,265 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 25th overall. This is the largest prime found in The Riesel Problem and PrimeGrid's sixth elimination. 58 k's now remain.

The discovery was made by Scott Brown (Scott Brown) of the United States using an Intel Core2 Duo E8400 @ 3.0GHz with 4 GB RAM running Windows 7. This computer took just over 7 hours and 25 minutes to complete the primality test using LLR. Scott is a member of the Duke University team.

The prime was verified on 28 May 2011 23:08:20 UTC, by Piotr M. Zalewski (Piotr M. Zalewski) of Poland. For more details, please see the official announcement.
29 May 2011 | 14:18:09 UTC · Comment


Mega Prime found for The Riesel Problem (Déjà vu)
Remarkably, another mega prime has been found during the Cinco de Mayo Challenge.

On 8 May 2011 15:43:27 UTC, PrimeGrid’s The Riesel Problem project eliminated k=415267 by finding the mega prime: 415267*2^3771929-1

The prime is 1,135,470 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 29th overall. This is the 2nd largest prime found in The Riesel Problem and PrimeGrid's fifth elimination. 59 k's now remain.

The discovery was made by Alexey Tarasov (Alexus78) of the Ukraine using an Intel Core2 Duo E6550 @ 2.33GHz with 1 GB RAM running Windows XP Professional. This computer took just over 10 hours and 18 minutes to complete the primality test using LLR. Alexey is a member of the Ukraine team.

The prime was verified on 13 May 2011 15:36:23 UTC, by Brett Melvold (AgentQ) of Australia. For more details, please see the official announcement.
13 May 2011 | 23:47:46 UTC · Comment


Mega Prime found for The Riesel Problem
On 8 May 2011 7:29:52 UTC, PrimeGrid’s The Riesel Problem project eliminated k=123547 by finding the Mega prime: 123547*2^3804809-1

The prime is 1,145,367 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 28th overall. This is the largest prime found in The Riesel Problem and PrimeGrid's fourth elimination. 60 k's now remain.

The discovery was made by Jakub Łuszczek (..:: Thor ::..) of Poland using an Intel Core i5 2500 @ 3.3GHz with 8 GB RAM running Windows 7 Home Premium x64. This computer took just over 4 hours and 35 minutes to complete the primality test using LLR. Jakub is a member of the Polish National Team.

The prime was verified on 11 May 2011 19:41:48 UTC, by Frans Englund (Snf*) of Sweden. For more details, please see the official announcement.
11 May 2011 | 22:52:38 UTC · Comment


The Cinco de Mayo Challenge in less than 3*2^3 hours
Come join us for the 5th day of the 5th month celebration. A 2^3 day Challenge is being offered on PrimeGrid's "The Riesel Problem" (LLR) application…ends on the 13th. There remains 61 k's in The Riesel Problem for which no primes have been found.

For more information, please see this forum post.
4 May 2011 | 19:40:01 UTC · Comment


BOINC Pentathlon
SETI.Germany is hosting the 2nd annual BOINC Pentathlon where all BOINC-Teams are invited to participate. This year, PrimeGrid has been chosen as the second of five disciplines. The Pentathlon will focus on PrimeGrid's GPU projects from 8 May 2011 to 13 May 2011.

For more information on this special event and to see the other projects selected, please visit BOINC Pentathlon Welcome page.
2 May 2011 | 14:46:04 UTC · Comment


The Cinco de Mayo Challenge in 3^2 days
In 3^2 days, come join us for the 5th day of the 5th month celebration. A 2^3 day Challenge is being offered on PrimeGrid's "The Riesel Problem" (LLR) application…ends on the 13th. That's a lot of prime numbers in the first 2 sentences. :) Let's continue the trend and find some primes during the Challenge. There remains 61 k's in The Riesel Problem for which no primes have been found.

For more information, please see this forum post.
26 Apr 2011 | 5:05:48 UTC · Comment


April's PRPNet Project - 5oB home stretch
Two thirds of the way through the month and we're in the home stretch. The 5oB double check is turning out to be like a good old fashioned tractor pull. The closer we get to the finish, the harder the task becomes. Now more that ever we need additional help to help stave off the decline in our daily rate…which has seen seven straight days of decline.

The higher numbers are starting to get the better of us and the naysayers are beginning to weigh down the sled. Let's throw some extra power on this and knock the naysayers off. :)

Please keep spreading the word. We still need more support to reach the goals. For more information, see this forum post.
20 Apr 2011 | 1:16:30 UTC · Comment


Subproject completion - 321 Prime Search (Sieve)
321 Prime Search (Sieve) subproject has reached the "optimal zone" and will be suspended on 22 April 2011. This means that no more work for 321 Prime Search (Sieve) will be added after 22nd, but outstanding work will be allowed to complete. 321 Prime Search (LLR) will not be affected and will continue running.

Once the work is depleted, project preferences will be automatically changed for people who have selected only 321 Prime Search in their preferences. Default subprojects will be selected, but you may wish to proactively choose a subproject or two.

For people fighting for a badge this may be a good opportunity to push if you are lacking just a few credits.
17 Apr 2011 | 8:38:49 UTC · Comment


April's PRPNet Project - 5oB
Half way through the month and steady progress continues. We are certainly making the naysayers sweat a little. The first goal is definitely within reach. A HUGE thanks to everyone who has answered the call for help. Let's keep the pressure up!!!

Please keep spreading the word. We still need more support to reach the other two goals...tell a teammate or two or three. :) For more information, see this forum post.
15 Apr 2011 | 21:37:28 UTC · Comment


Mega Prime found for The Riesel Problem
On 5 Apr 2011 7:13:12 UTC, PrimeGrid’s The Riesel Problem project eliminated k=65531 by finding the Mega prime: 65531*2^3629342-1

The prime is 1,092,546 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 29th overall. This is the largest prime found in The Riesel Problem and PrimeGrid's third elimination. 61 k's now remain.

The discovery was made by Adrian Schori of Switzerland using an Intel Core i5 750 @ 2.67GHz with 4 GB RAM running Mac OS X. This computer took just over 5 hours and 12 minutes to complete the primality test using LLR. Adrian is a member of SwissTeam.NET.

For more details, please see the official announcement.
12 Apr 2011 | 2:54:24 UTC · Comment


April's PRPNet Project - 5oB
A third of the way through the month and our effort to help out the successful "Five or Bust" project is making steady progress.

If you are in search for your PSA badge (or upgrade the one you have), now is a good opportunity to get that done as well as give to a worthy cause. :) PSA credit is available. If you are new to PRPNet, individualized "pre-set" packages can be made where all you'll have to do is download, double click a couple of times and be quickly contributing to the project.

We have updated goals for the month. Please see if you can help us reach them. For more information, see this forum post.
10 Apr 2011 | 2:52:21 UTC · Comment


The Marie-Sophie Germain Challenge - Final
After a relatively quick "clean-up", the results are final. What an excellent turnout for the Challenge. Over 120 single primes were returned during the Challenge. Unfortunately, no luck with finding a Sophie Germain or twin prime.

Over 1.3M tasks were completed resulting in over 11.3M Challenge points awarded. Congratulations to Ukraine as the top team and Alexus78 as the top individual. For more stats and information, please see this forum post.

Thank you again to everyone. We appreciate your participation and hope to see you at the Cinco de Mayo Challenge. Come join us 5-13 May for an 8 day celebration on The Riesel Problem (LLR) application! Currently, there are 61 k's remaining that need to be eliminated.
9 Apr 2011 | 14:16:07 UTC · Comment


The Marie-Sophie Germain Challenge in 3 hours
Come join us as we pay tribute to Marie-Sophie Germain with a 2 day (1-3 April) Challenge on the Sophie Germain Prime Search project.

For more information, please see this forum post.
1 Apr 2011 | 15:00:22 UTC · Comment


The Marie-Sophie Germain Challenge in 2 days
Marie-Sophie Germain was born on April 1, 1776, in Paris, France. She was an extraordinary "French mathematician who made important contributions to the fields of differential geometry and number theory and to the study of Fermat's Last Theorem." (Wiki) Come join us as we pay tribute to her with a 2 day (1-3 April) Challenge on the Sophie Germain Prime Search project.

For more information, please see this forum post.
30 Mar 2011 | 17:35:27 UTC · Comment


Planned maintenance on Monday
We are planning a short downtime on Monday to install additional hardware and reorganize network in the server rack. You may wish to increase work cache slightly if you are running with a very low cache size.

[update 15:25UTC] Maintenance has been completed successfully.
12 Mar 2011 | 13:54:05 UTC · Comment


Generalized Fermat Mega Prime
On 08 Mar 2011 10:35:34 UTC, PrimeGrid's PRPNet found a Generalized Fermat mega prime: 40734^262144+1

The prime is 1,208,473 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 2nd for Generalized Fermat Primes and 26th overall.

The discovery was made by Senji Yamashita of Japan using an Intel Core 2 Quad Q9450 @ 2.66GHz with 2GB RAM, running Windows 7 Professional 64bit. This computer took 4 hours and 29 minutes to complete the primality test using pfgw64. Senji is a member of the PrimeSearchTeam.

For more details, please see the official announcement.
9 Mar 2011 | 21:21:03 UTC · Comment


World Record 321 Prime
On 21 Feb 2011 21:45:32 UTC, PrimeGrid’s 321 Prime Search found another Mega Prime: 3*2^7033641+1

The prime is 2,117,338 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 14th overall. This is the second mega prime and the largest for the 3*2^n+1 form. It is also the second largest found mega prime using LLR and PrimeGrid's 10th overall mega prime.

The discovery was made by Michael Herder using an Intel Core i7 920 @ 2.67GHz with 6 GB RAM running Windows 7 Ultimate x64. This computer took just over 17 hours and 24 minutes to complete the primality test using LLR. Michael is a member of the BOINCstats team.

For more details, please see the official announcement.
1 Mar 2011 | 4:03:32 UTC · Comment


World Maths Day Challenge in 15 hours
The World Maths Day games are in full swing. Head over there to test your math skills. But don't forget to check back here in less than 15 hours. A 24 hour Challenge is being offered on PrimeGrid's The Riesel Problem (Sieve).

For more information, please see this forum post.
1 Mar 2011 | 3:48:14 UTC · Comment


World Maths Day Challenge in 3 days
Time to dust off the cobwebs and start recalling all your math knowledge. PrimeGrid's 2011 Challenge series continues with the "World Maths Day Challenge". Come join the competition here as well as at the World Maths Day games. World Maths Day begins earlier than the Challenge so head there now to register before it's too late.

For more information, please see this forum post.
26 Feb 2011 | 19:35:20 UTC · Comment


World Record Generalized Woodall Prime
On 24 Feb 2011, 17:27:31 UTC, PrimeGrid’s PRPNet found the largest known generalized Woodall prime: 404882*43^404882-1

The prime is 661,368 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for generalized Woodall primes and 71st overall.

The discovery was made by Ricky L. Hubbard of the United States using an AMD Athlon II X4 635 @ 2.90GHz with 8GB RAM, running Windows 7. This computer took about 4 hours and 15 minutes to complete the probable prime test using pfgw64 and a little over 30 hours 3 minutes to complete the primality test again using pfgw64. Ricky is a member of the AMD Users Team.

For more details, please see the official announcement.
25 Feb 2011 | 6:55:13 UTC · Comment


World Maths Day Challenge
PrimeGrid's 2011 Challenge Series continues with the "World Maths Day Challenge". World Maths Day is a day to promote numeracy through games and competition. It has been created for students aged 4 - 18 years with the addition for the first time this year of an adult category, ages 19 to 119. Compete against others around the world in live games of mental arithmetic.

In honor of World Maths Day, PrimeGrid is offering 24 Challenge (1-2 March) on The Riesel Problem (Sieve) application. For more information, please see this forum post.

p.s. Please spread the word about World Maths Day. Their goal this year is to achieve 1 billion correct answers.
22 Feb 2011 | 17:14:53 UTC · Comment


World Record Generalized Fermat Prime
On 8 Feb 2011 09:38:57 UTC, PrimeGrid’s PRPNet found the largest known Generalized Fermat Prime: 145310^262144+1

The mega prime is 1,353,265 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Generalized Fermat Primes and 23rd overall.

The discovery was made by Ricky L Hubbard of the United States using an AMD PHENOM II X6 1090t @ 3.2GHz with 8GB RAM, running Windows 7. This computer took about 11 hours to probable prime (PRP) test with GenefX64 and 48 hours and 15 minutes to complete the primality test using pfgw64. Ricky is a member of the AMD Users team.

For more details, please see the official announcement.
10 Feb 2011 | 6:20:23 UTC · Comment


State of the validator after the challenge
Because of the massive amount of work that we received during the challenge, we have a big backlog for the validator to process. While it may seem that validation has stopped, it is simply not true, and validator is working through the backlog. This backlog also causes problems displaying pending credit page for some users.

We estimate that the valitator will catch up in less than a week. Until then credit for newly reported results may be slightly delayed.
8 Feb 2011 | 10:29:13 UTC · Comment


The Year of the Rabbit Challenge Preliminary results
What an amazing amount of work completed and a ton of primes found. Although the validator was overwhelmed early on, the server held up to the stress (fortunately this did not affect scoring).

Once again, it was exciting to see the top teams go neck and neck to the wire. This Challenge will set several records. We'll need a few days to process the data. A lot of xGFN testing is left to do on the found primes so expect them to roll out over the next few days. :)

The Challenge is over and now the "clean up" process begins. We are expecting roughly a week but hoping for less.

Official results are most likely less than a week away, but for preliminary results, please see this forum post. Thank you to everyone who participated.
6 Feb 2011 | 20:38:05 UTC · Comment


The Year of the Rabbit Challenge begins
The Challenge has begun, but first you must answer these three questions before you cross the bridge of primes. What is your name? What is your quest? What is the name of the prime where k=n?

For more information about the Challenge, please see this forum post. Best of Luck to everyone!
3 Feb 2011 | 18:00:25 UTC · Comment


The Year of the Rabbit Challenge in 24 hours
In the immortal words of Tim the Enchanter, "I warned you! But did you listen to me? Oh, no, you knew it all, didn't you? Oh, it's just a harmless little bunny, isn't it?" Watch out for those primes...some of them can be quite hard to tame. Beware of the ones with nasty big pointy teeth. :)

A 3 day (3-6 Feb) Year of the Rabbit Challenge is being offered on PrimeGrid's Proth Prime Search (LLR) application. For more information, please see this forum post.
2 Feb 2011 | 22:33:49 UTC · Comment


The Tour de Primes begins!
Come join us in laid-back competition in tribute to the number 2...the first prime and the only even prime. The prizes are simple colored jerseys . Yellow for the most primes, Green for the highest prime score, and Checkered for the most primes on 5 Feb. No pressure or stress other than what you put on yourself. :) For more information, please see Tour de Primes 2011. 1 Feb 2011 | 0:01:32 UTC · Comment


The Year of the Rabbit Challenge in 3 days
"Thou shalt count to three, no more, no less. Three shalt be the number thou shalt count, and the number of the counting shalt be three. Four shalt thou not count, nor either count thou two, excepting that thou then proceed to three. Five is right out. Once the number three, being the third number, be reached, then lobbest thou thy Holy Host of Antioch towards thou task, who being naughty in my sight, shall snuff it." ;)

A 3 day (3-6 Feb) Year of the Rabbit Challenge is being offered on PrimeGrid's Proth Prime Search (LLR) application. For more information, please see this forum post.
31 Jan 2011 | 19:19:17 UTC · Comment


The Year of the Rabbit Challenge
You know what they say about rabbits? Well, we hope it's the same for primes during this Challenge. :D Come join us as we propagate the Top 5000 list with a litter of kits...I mean, a bunch of primes! It's a GREAT opportunity for you to find a prime for yourself! Who knows, there may even be the rare Fermat number divisor. :)

A 3 day (3-6 Feb) Challenge is being offered on PrimeGrid's Proth Prime Search (LLR) application. For more information, please this forum post.
29 Jan 2011 | 2:05:23 UTC · Comment


Tour de Primes 2011
February is just a few days away which means it is almost time for the 3rd annual Tour de Primes. 2 is the first prime number...and the only even one. Therefore, we have declared February, the 2nd month, as prime month.

We're offering a small informal competition in tribute to this unique prime number. There are no points to be gained or awards to be won...just a simple colored jersey (Yellow, Green, and Checkered) at the end of the month. No pressure or stress other than what you put on yourself. :) For more information, please see Tour de Primes 2011.
27 Jan 2011 | 18:26:40 UTC · Comment


Mega Prime found for The Riesel Problem
On 14 Jan 2011 9:03:07 UTC, PrimeGrid’s The Riesel Problem project eliminated k=428639 by finding the Mega prime: 428639*2^3506452-1

The prime is 1,055,553 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 29th overall. This is the 2nd largest prime found in The Riesel Problem and PrimeGrid's second elimination in 2 months. 62 k's now remain.

The discovery was made by Brett Melvold of Australia using an Intel i7 920 @ 2.67GHz with 6GB RAM, running Windows 7. This computer took 11 hours and 13 minutes to complete the primality test using LLR. Brett is a member of the BOINC@AUSTRALIA team.

For more details, please see the official announcement.
18 Jan 2011 | 17:31:53 UTC · Comment


GFN PRPNet Challenge - Results
The GFN Prime Search PRPNet Challenge was a nice success. Congratulations to Senji Yamashita (s-yama) as the top individual scorer. Additional congratulations goes out to Amy Chambers (Buckeye74) who found PrimeGrid's first GFN prime in this search. This prime was quickly followed less than an hour and a half later by another prime discovered by Ross Goudie (Ross*). The goal of finding at least one GFN prime was achieved. For complete scores, please see here.

The search continues with the month long goals of finding a prime at each of the following N's: 65536, 262144, 524288. For more information, please see the GFN Prime Search. BTW, the GPU really shines at the higher N's. :)
17 Jan 2011 | 15:59:24 UTC · Comment


January's PRPNet Challenge Project on GFN
Pierre de Fermat (1601-1665) is often called the "Prince of Amateurs." It is in his honor that the first PRPNet Challenge of 2011 is on the Generalized Fermat Number (GFN) Prime Search. A 3 day Challenge is being offered starting 12 January 2011 00:00 UTC on PrimeGrid's PRPNet. NOTE: PrimeGrid's BOINC Challenge series doesn't start until 3 February 2011.

With the breakthrough of porting Genefer 2.2.0 to the GPU (CUDA), the search has become much more attractive. Testing times for the higher N's have been drastically reduced. NOTE: GPU app requires double precision support. Come be the first at PrimeGrid to report a Top 5000 prime found by a GPU.

For more information, please see this forum thread.
9 Jan 2011 | 8:31:08 UTC · Comment


Sierpinski/Riesel Base 5 Project
With the success of The last 10 Days of 2010 PRPNet Challenge, we are happy to announce that a collaboration has been formed between PrimeGrid and the Sierpinski/Riesel Base 5 Project. This is a combination of the SoB and TRP projects, except for the base of 5 instead of 2.

SR5 will enter PrimeGrid's Project Staging Area. The goal will be to make 2011 the best year of the project in terms of work completed. For more information about the SR5 Project, please see this forum post.
7 Jan 2011 | 19:59:27 UTC · Comment


Happy New Year 2011!
Happy New Year 2011...a prime number year! Here's a little trivia from Prime Curios!:2011 - Two thousand "eleven" is the sum of 11 consecutive primes. Can you find them? [Post] 1 Jan 2011 | 0:56:37 UTC · Comment


2010 Challenge Series Final Rankings
PrimeGrid's 2010 Challenge Series is final. This year saw tremendous growth as well as tougher competition. The expansion of "scoring positions" was a nice success and allowed more users and teams to participate in the rankings.

Congratulations to SETI.USA as the top team and Mr. Hankey as the top individual. They are the winners of PrimeGrid's 2010 Challenge Series. For complete, extended rankings please see: Individuals | Teams

As always, thank you for your help and support. We continue to be humbled by your participation. None of this is possible without YOU! :) Have a safe and happy Holiday season. See you next year for PrimeGrid's 2011 Challenge Series!
31 Dec 2010 | 18:49:09 UTC · Comment


Unexpected downtime
We had some downtime because of database issues. They should be resolved and the work should be flowing fine now. 31 Dec 2010 | 14:15:52 UTC · Comment


SR5 PRPNet Challenge - fourth and fifth prime!
The stars must have aligned today as two SR5 primes were found in the Challenge. One by Murphy Babb (his second) of the United States and one by Sascha Beat Dinkel of Switzerland. Murphy's prime (3938*5^558032-1) is 390,052 digits and ranks 3rd for SR5 primes and 218th overall. Sascha's prime (151026*5^559670-1) is 391,198 digits and ranks 2nd for SR5 primes and 216th overall.

This is a GREAT way to lead into the final 24 hours of the Challenge. Looks like we've even hit the 5 primes request. What more is there to ask for now??? :D How about an SR5 prime for everyone participating? Is that too lofty of a goal?

If you are interested in participating, please see the Last 10 Days of 2010 PRPNet Challenge post.
31 Dec 2010 | 2:50:10 UTC · Comment


SR5 PRPNet Challenge - third prime!
Matthew Poulter of the United Kingdom has found the third prime of the SR5 PRPNet Challenge. It is 385,673 digits and ranks 2nd for SR5 primes and 224th overall in the Top 5000 primes database!

105782*5^551766-1

Now that 2010 has become the best year of the project, let's see how far we can push it. With just over 2 days left in the Challenge, we have an opportunity to find a couple more primes and make 2010 head and shoulders above the rest.

If you are interested in participating, please see the Last 10 Days of 2010 PRPNet Challenge post.
29 Dec 2010 | 20:41:02 UTC · Comment


SR5 PRPNet Challenge - second prime!
Murphy Babb of the United States has found the second prime of the SR5 PRPNet Challenge. And what a nice one it is...coming in ranked 4th for SR5 primes and 265th overall in Top 5000 primes database!

183916*5^519597-1

This prime marks a nice milestone for the SR5 project. Removing k=183916 brings the sieve file to less than 3M terms remaining (to n=2M). The current sieve file has 2,982,533 terms in 181 sequences.

Only one more prime is needed to make 2010 the best year of the SR5 project in regards to prime score. If you are interested in participating, please see the Last 10 Days of 2010 PRPNet Challenge post.
27 Dec 2010 | 21:32:59 UTC · Comment


SR5 PRPNet Challenge
Michał Gasewicz of Poland has found the first prime of the SR5 PRPNet Challenge. Yes, the same "lucky" person who found the World Record Primorial prime last week...even with the same computer!!! This is most definitely a good holiday season for him. :)

53542*5^515155-1

Only two more primes are needed to make 2010 the best year of the SR5 project in regards to prime score. If you are interested in participating, please see the Last 10 Days of 2010 PRPNet Challenge post.

NOTE: Anyone needing assistance in joining the PRPNet Challenge, an individualized package can be created for you. All you'd have to do is download, unzip, and double click a few times and...PRPNet will do the rest. :) Builds are available for Linux, Mac, and Windows.
26 Dec 2010 | 1:10:03 UTC · Comment


World Record Primorial Prime
On 20 Dec 2010, 08:05:22 UTC, PrimeGrid’s PRPNet found the largest known Primorial prime: 843301#-1

The prime is 365,851 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Primorial primes and 260th overall.

The discovery was made by Michał Gasewicz of Poland using an Intel dual Xeon E5520 @ 2.27GHz with 12GB RAM, running 64 bit Linux. This computer took about 71 hours and 20 minutes to complete the primality test using pfgw x64. Michał is a member of the BOINC@Poland team.

For more details, please see the official announcement.
24 Dec 2010 | 15:29:51 UTC · Comment


The Winter Solstice Challenge - Final
The Winter Solstice is here!!! The solstice fires are the brightest they have ever been at PrimeGrid. The fuel came from an unprecedented amount of factors found. This Challenge benefited not only PrimeGrid's Proth Prime Search project but also the entire Riesel prime search community. A wonderful holiday gift to all those involved. :)

1.3P of sieve work was crunched in 434K tasks. A HUMONGOUS sieve that would have been impossible to do without Ken Brazier's help. A special thanks to him for his modifications to tpsieve as well as his port to GPU's.

Congratulations to Sicituradastra. as the top team and Steve* as the top individual. Remember, the top 100 individual and top 50 team places earn points for this Challenge. For more stats and information, please see this forum post.

This concludes PrimeGrid's 2010 Challenge Series. Overall final results will be posted soon. Thank you to everyone who participated this year. We wish you a Happy Holidays and hope to see you next year!
22 Dec 2010 | 5:42:46 UTC · Comment


Primorial prime found in PRPNet
Tis the season to be merry!!! :) With last week's Factorial prime and today's Primorial prime, this holiday is shaping up to be quite generous.

The prime is only the 19th known p#-1 form and the 1st discovered in 18 years. It is the 1st found of either form (p#+1, p#-1) in over 9 years. Needless to say, this is exceptionally rare. It almost doubles the size of the previous record of 392113#+1 (169966 digits).

More details to come once the double check is complete.
20 Dec 2010 | 16:13:55 UTC · Comment


The Winter Solstice Challenge in 24 hours
Soon the winter festival will begin. Come warm yourself by the Solstice fires. PrimeGrid's Challenge series ends 2010 with a 3 day (18-21 Dec) Challenge on PPS (Sieve). 32&64 bit builds are available for Mac, Linux, and Windows as well as CUDA/ATI (OpenCL) for the GPU. For more information, please see this forum thread. 17 Dec 2010 | 17:08:48 UTC · Comment


The Winter Solstice Challenge in 3 days
PrimeGrid's Challenge series ends 2010 with the Winter Solstice Challenge. Please come join us in observing Nature's ending/beginning of a cycle...a Winter Festival on PrimeGrid's only GPU accessible project. A 3 day (18-21 Dec) Challenge is being offered on PPS (Sieve). 32&64 bit builds are available for Mac, Linux, and Windows as well as CUDA/ATI (OpenCL) for the GPU. For more information, please see this forum thread. 15 Dec 2010 | 17:41:44 UTC · Comment


Downtime
We are going to have a short downtime today at around 12:00 UTC to install additional memory for the database server. Both BOINC server and website will not be available at that time.

Update 14:00 UTC: maintenance has been completed, and we are now running with 16GB of available memory. We will continue tweaking MySQL, so you can still expect short downtimes.
15 Dec 2010 | 9:19:03 UTC · Comment


World Record Factorial Prime
On 14 Dec 2010 02:12:42 UTC, PrimeGrid’s PRPNet found the largest known Factorial prime: 103040!-1

The prime is 471,794 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Factorial primes and 136th overall.

The discovery was made by James Winskill of New Zealand using an Intel Core 2 Duo @ 2.13GHz with 2GB RAM, running 32 bit Windows XP. This computer took about 46 hours and 42 minutes to complete the primalty test with pfgw. James is a member of the PrimeSearchTeam.

For more details, please see the official announcement.
15 Dec 2010 | 3:49:06 UTC · Comment


LLR 3.8.4 released for all LLR projects
Over the weekend, LLR V3.8.4_final for Linux and Mac was released for all LLR projects. Windows is still waiting for a new wrapper. Most hosts should see from 15%-20% speed up in primality testing. This will be welcomed relief in the longer LLR projects (SoB, PSP, Cullen, Woodall, 321 & TRP). Good Luck!

LLR V3.8.4 from Jean Penne uses the final V26.4 gwnum code from George Woltman.
13 Dec 2010 | 4:51:43 UTC · Comment


Mega Prime found for The Riesel Problem
On 21 Nov 2010, 11:14:00 UTC, PrimeGrid’s The Riesel Problem project eliminated k=191249 by finding the Mega prime: 191249*2^3417696-1

The prime is 1,028,835 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 29th overall. This is the 2nd largest prime found in The Riesel Problem and the first k elimination in over 2 1/2 years. 63 k's now remain.

The discovery was made by Jonathan Pritchard of the United Kingdom using an AMD Phenom 9950 with 8GB RAM, running Windows 7. This computer took 7 hours and 31 minutes to complete the primality test using LLR. Jonathan is a member of the Turan@BOINC team.

For more details, please see the official announcement.
3 Dec 2010 | 0:19:20 UTC · Comment


Official release of tpsieve for PPS (Sieve)
PrimeGrid is excited to finally announce the official release of the tpsieve application in the PPS (Sieve) project. Linux, Mac, and Windows platforms for 32/64 bit are all supported as well as CUDA and OpenCL (ATI). Only Mac OpenCL is NOT currently available. Also, OpenCL requires an app_info file to run due to a scheduling request issue. However, we hope to have that problem resolved before the next Challenge (18-21 December). NOTE: Windows GPU users should update to .NET Framework 3.5.

tpsieve, based on Geoff Reynolds' original code, is a revolution to k*2^n+1/-1 sieving. Thanks in large part to Ken Brazier's updates and modifications to include simultaneous +1/-1 dat-less sieving as well as his ports to the GPU, tpsieve has changed the landscape of sieving and is now providing incredible support to the prime finding community.

Thank you Ken!!!
1 Dec 2010 | 16:31:28 UTC · Comment


The Leonids Challenge - Final
The results are final. What a splendid show for both the Leonids and the Challenge. Over 100 single primes were returned during the Challenge...greatly exceeding our expectation. Unfortunately, no luck with finding a Sophie Germain or twin prime.

719K tasks were completed resulting in over 6.1M Challenge points awarded. Congratulations to Team Norway as the top team and shanky123 as the top individual. For more stats and information, please see this forum post.

Thank you to everyone who participated!!! The final Challenge of 2010 is the Winter Solstice Challenge...come join us 18-21 December for 3 days on the Proth Prime Search (Sieve) application! As this year's only GPU application Challenge, it's sure to light the solstice fires!!!
29 Nov 2010 | 22:17:04 UTC · Comment


Prime found in The Riesel Problem!!!
The first prime in almost 2 1/2 years has been discovered for The Riesel Problem. More details to come after the primary finder has responded.

EDIT (29 Nov): Still awaiting contact from UserID 53352 (Jonathan Pritchard) of the Turan@BOINC team.
24 Nov 2010 | 16:51:22 UTC · Comment


The Leonids Challenge - Preliminary results
What a splendid show for both the Leonids and the Challenge. Once again, it was exciting to see the top 2 teams go neck and neck to the wire. Also, through the top 100 users, there are many positions separated by a single task. So far, no luck with finding a Sophie Germain or twin prime, but there were over 110 single primes returned during the Challenge...greatly exceeding our expectation.

The Challenge is over and now the "clean up" process begins. As a nice contrast to the Calendula Challenge, this one is shaping up to be very short.

Official results are most likely less than a week away, but for preliminary results, please see this forum post. Thank you to everyone who participated.
19 Nov 2010 | 4:02:56 UTC · Comment


The Leonids Challenge in 24 hours
Come join us at the peak of the Leonids for a 24 hour Challenge on the Sophie Germain Search (LLR) project. A Sophie Germain prime or even a twin prime may be waiting for you. ;) For more information, please see this forum post. 16 Nov 2010 | 17:09:40 UTC · Comment


The Leonids Challenge in 3 days
In 3 days, the Leonids Challenge will begin. Come watch the "falling stars" and hopefully find an elusive Sophie Germain prime or even a twin. A 24 hour (17-18 November) Challenge is being offered on The Sophie Germain Prime Search (LLR) application. For more information, please see this forum post. 14 Nov 2010 | 15:05:08 UTC · Comment


Proth Prime Search (Sieve)
The PPS (Sieve) will be pausing soon. When the current buffer empties and all outstanding work has been completed and validated, we'll be switching applications from ppsieve to tpsieve. This will allow for combined sieving of both +1 and -1 forms. For more information, please see this thread.

We hope to resume in less than a week. :)
9 Nov 2010 | 18:37:52 UTC · Comment


Preparing for Leonids II
This is a reminder that the 2nd test run is coming up today Sunday, 7 Nov 2010 18:00 UTC. Again it will be on the PPS (LLR) project. We'll be looking for a good balance between request handling speed and amount of tasks in memory. For this one, we'll need as many hosts as possible hitting the server at the start.

For results of the 1st test run, please see this post.

Thank you for your help! :)
7 Nov 2010 | 7:02:36 UTC · Comment


Test run results
The test run today was very productive. Thank you to everyone who participated. For details on what we learned, please see this post.

A new one hour test run has been scheduled for Sunday, 7 Nov 2010 18:00 UTC. Again it will be on the PPS (LLR) project. We'll be looking for a good balance between request handling speed and amount of tasks in memory. For this one, we'll need as many hosts as possible hitting the server at the start.

Thanks again for your help! :)
3 Nov 2010 | 21:26:34 UTC · Comment


Preparing for Leonids
The Leonids Challenge is coming up on 17 November 2010. The project is the Sophie Germain Prime Search which uses LLR to primality test candidates to find twin or Sophie Germain primes. With the new LLR v3.8.2 app, testing times have dropped in some cases as much as 20%. Therefore, while we still have time, we'd like to conduct test runs to evaluate server load.

The first run will be 3 November 2010 at 18:00. We'd like to run a 1 hr test on PPS (LLR) and produce as much stress as possible. We'll be monitoring load and making changes as necessary. If PPS (LLR) can run well under load, then SGS will as well with its longer tasks. For information, please see this forum thread.
1 Nov 2010 | 16:36:27 UTC · Comment


Work stats file move
Work stats file detailing user work done per subproject will be moved from /stats/ to /stats_work/ on Monday, November 8th. The new location is already live; everyone who is using the work stats file should update their scripts.

Note that the location change does not affect standard stats files.
1 Nov 2010 | 10:32:02 UTC · Comment


PSP/SoB (Sieve) nears end
The work buffer for PSP/SoB (Sieve) has reached 0. All that remains is work in progress. Since the deadline for these tasks is 7 days, we expect completion in a week or two depending on the number of expired tasks. Please see this post for updates on remaining tasks.

Suspension of the this sieve is a GREAT milestone. Congratulations to everyone who participated.
19 Oct 2010 | 2:28:06 UTC · Comment


The Calendula Challenge - Preliminary results
For such a marathon of a Challenge, it was exciting to see the many close battles taking place. What's amazing is how close the top two spots were for both the team and individual categories. Although no one found the golden flower (PSP prime), excellent progress was made advancing the search.

The Challenge is over and now the "clean up" process begins. If you have the resources, please consider joining in the "clean up". We greatly appreciate any help. However, we fully understand the need/desire to "move on".

Official results are probably 6-8 weeks away, but for preliminary results, please see this forum post. Thank you to everyone who participated.
8 Oct 2010 | 3:13:56 UTC · Comment


World Record Factorial Prime
On 04 Oct 2010, 15:01:15 UTC, PrimeGrid’s PRPNet found the largest known Factorial prime: 94550!-1

The prime is 429,390 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Factorial primes and 155th overall.

The discovery was made by Dmitry Domanov of Russia using an Intel Intel Xeon E5310 @ 1.60GHz with 4GB RAM, running 32 bit Windows 2003 Server. This computer took 24 hours and 19 minutes to complete the prime test using pfgw. Dmitry is a member of Team Russia.

For more details, please see the official announcement.
6 Oct 2010 | 3:32:43 UTC · Comment


PSP/SoB (Sieve) to be suspended
13 October 2010 is approaching. This will be the last insertion date for PSP/SoB (Sieve) before it is suspended. Until then, the queue will be kept full for anyone wishing to complete their last effort on this project.

This is a major accomplishment for both the Prime Sierpinski Problem and the Seventeen or Bust projects. For more information, please see this forum thread.
5 Oct 2010 | 18:23:56 UTC · Comment


The Calendula Challenge - 3 days remain!
The flowers are starting to loose their fragrance and their petals are falling. Unfortunately, the long sought after golden flower has yet to bloom. :(

With 3 days remaining, it's time to start crunching those last tasks and emptying the cache. For those "moving on" after the Challenge AND have their last WU's processing, now would be a good time to set no new work. For more information, please see this forum post.
4 Oct 2010 | 14:52:36 UTC · Comment


The Calendula Challenge in 24 hours
The Calendula Challenge will soon begin. A 13 day (24 Sept - 7 Oct) Challenge is being offered on The Prime Sierpinski Problem (LLR) application. For more information, please see this forum post.

Come early and participate in the "All hands on deck" request for PPS (LLR). This is a GREAT warm-up ahead of the Challenge.
23 Sep 2010 | 18:08:46 UTC · Comment


The Calendula Challenge in 3 days
In 3 days, the Calendula Challenge will begin. Come watch the flowers bloom and hopefully find a 3 million digit Mega Prime! A 13 day (24 Sept - 7 Oct) Challenge is being offered on The Prime Sierpinski Problem (LLR) application. For more information, please see this forum post.

Also, come visit the forum and read about the "All hands on deck" request for PPS (LLR). This is a GREAT warm-up ahead of the Challenge.

21 Sep 2010 | 16:42:30 UTC · Comment


New badge level
A new badge level, Ruby, has been added, and badge level for Amethyst has been lowered.

The current badge levels are:


  • For LLR projects: 10 / 100 / 500 / 1000 / 2000 thousand credits;
  • For Sieve/AP projects: 20 / 200 / 1000 / 2000 / 4000 thousand credits.


Here's an example of the new badge for your viewing pleasure: 19 Sep 2010 | 9:48:48 UTC · Comment


The Calendula Challenge
PrimeGrid's Challenge Series continues with the "Calendula Challenge". Come join us on this year's most grueling Challenge...of course, it will be the most rewarding Challenge as well for Challenge Points. A 13 day (24 Sept - 7 Oct) Challenge is being offered on The Prime Sierpinski Problem (LLR) application. A prime, if found, will be over 3 million digits long and rank as the 11th largest prime. For more information, please see this forum post. 14 Sep 2010 | 15:03:28 UTC · Comment


Planned maintenance tonight
Tonight we might have a downtime because of some maintenance in the datacenter. Fill your caches!

[update] After the maintenance the servers did not respond so we had to do a hard reboot. Hopefully everything is fine now.
24 Aug 2010 | 15:11:01 UTC · Comment


The Dog Days of Summer in 24 hours
When will the end come to this summer heat??? As soon as Sirius is separated from the sun!!! In 24 hours, come join us to help hasten Sirius' departure and thus, bring back cooler days. A 48 hour Challenge is being offered on the 321 Prime Search (Sieve). For more information, please see this forum thread. 19 Aug 2010 | 18:17:32 UTC · Comment


The Dog Days of Summer in 2 days
The time draws near to the chase. Sirius must be driven away from the Sun so that we can rid ourselves of this long hot sweltering summer (Northern Hemisphere). In 2 days, the Dog Days of Summer Challenge will begin. The 48 hour Challenge is being offered on PrimeGrid's 321 Prime Search (Sieve) application. Please come join us as we quicken the return of cooler days. :) For more information, please see this forum thread. 18 Aug 2010 | 14:18:51 UTC · Comment


PrimeGrid Donation Drive 2010 Fall
PrimeGrid is a project that is not financed by universities or commercial entities. In fact, all of our funding comes from the community, most of it through the donations page and a small amount through Google ads on the site. In the previous months donations were enough to cover all expenses running the website, however, the last few months have been particularly bad and just paying for server collocation has cut deep into our emergency funds.

It is never easy to be asking for money, but it has come to the point where we have to. We currently have money to keep the servers running for two more months. After that, we either shut down or throttle down significantly, which would be a shame having established PrimeGrid as a significant power in the prime number community, and having received uncountable hours of support from the members.

Therefore, we are launching PrimeGrid Donation Drive 2010 Fall. We have set the target to €4000, which would allow us continue the service for a whole year and would also restore our emergency funds.

No matter how small the donation, it still helps! However, we have to keep the minimum amount at €2 because of PayPal fees (if you prefer to donate through bank transfer, we have bank accounts in the Netherlands, Germany, Poland and Lithuania - please write a private message to me and the details will be sent to you).

To help keep the project running, please visit donations page, select the donation drive item and make a donation that you feel is suitable. Thank you in advance!

Update 2010-08-17 07:30 Big thanks to everyone who has donated already, we have almost reached 15% of the target amount. In addition, we now have a German bank account for direct transfer. If you want to make a direct deposit, please let me know by a private message.

Update 2010-08-18 15:30 By now we have almost reached 30%! Thank you for incredible support! In addition, Polish bank account has been added to the list for direct transfers.
16 Aug 2010 | 15:18:22 UTC · Comment


The Dog Days of Summer Challenge
The Dog Days are approaching! In just 10 days, PrimeGrid's Challenge series continues with the Dog Days of Summer Challenge. Please come join us in ushering an end to the hot sweltering days of summer. A 2 day (20-22 August) Challenge is being offered on PrimeGrid's 321 Prime Search (Sieve) application. Builds are available for Linux, Mac and Windows. For more information, please see this forum thread. 10 Aug 2010 | 13:37:09 UTC · Comment


The Full Moon Challenge - 24 hrs to go
There is coming soon a gathering of Warewolves and Prime Hunters. Be sure not to mix the two groups up or you might find yourself surrounded by blood thirsty animals!! ;) However, some might say that the two groups are NOT mutually exclusive. :D Come join us this Full Moon for a sporting "hunt" of Top 5000 primes in the Proth Prime Search (LLR) project. Application builds are available for Mac, Linux, and Windows. For more information, please see this forum thread. 24 Jul 2010 | 18:20:23 UTC · Comment


The Full Moon Challenge
Come howl at the moon with us and "hunt" for Top 5000 primes. It's a GREAT opportunity for you to find one for yourself! Who knows, there may even be the rare Fermat number divisor. :) We hope to establish a single day record for finding Top 5000 primes!

A 24 hour Challenge (25 July) is being offered on PrimeGrid's Proth Prime Search (LLR) application. Builds are available for Mac, Linux, and Windows. For more information, please see this forum thread.
21 Jul 2010 | 5:42:44 UTC · Comment


PSP finds another Mega Prime
The Prime Sierpinski Project has discovered their third Mega Prime: 90527*2^9162167+1. It is 2,758,093 digits long and will rank as the 12th largest known prime. The project has now found 18 primes total. There are 11 primes left to solve the Prime Sierpinski Problem. For more information, please see this forum post. 1 Jul 2010 | 18:40:10 UTC · Comment


9 hours til the Birthday/Summer Solstice Challenge
9 hours remain til the "Birthday/Summer Solstice Challenge". Come join us in a 5 day celebration of PrimeGrid's 5th birthday. The 16-21 June Challenge on the The Riesel Problem (Sieve) application will culminate with a finale on the Summer Solstice. For more information, please see this forum post. 16 Jun 2010 | 2:34:37 UTC · Comment


100M Cobblestones
A belated congratulations to shanky123 of Norway, for becoming the first single user account to reach 100M cobblestones (10 June) at PrimeGrid. An outstanding and amazing accomplishment after being here for just over 9 months.

Additionally, BOINCstats has just become only the 5th team to surpass 100M cobblestones. Congratulations all around.
15 Jun 2010 | 21:21:19 UTC · Comment


Unexpected outage
We had an unexpected network and power outage at the datacenter where PrimeGrid and BOINCstats are hosted, resulting in downtime of about an hour. The service has been restored now.

Update 19:01 UTC. We will remain down until database verification completes and we are sure we have no problems.
Update 19:20 UTC. Database has been checked and we're now sending and receiving work.
13 Jun 2010 | 18:37:00 UTC · Comment


7 days til the Birthday/Summer Solstice Challenge
Just under a week remains til the "Birthday/Summer Solstice Challenge". Come join us as we celebrate PrimeGrid's 5th birthday. A 5 day (16-21 June) Challenge is being offered on The Riesel Problem (Sieve) application. Note the special start time of 11:28 UTC so that the Challenge can end exactly on the Summer Solstice. For more information, please see this forum post. 9 Jun 2010 | 14:19:25 UTC · Comment


PrimeGrid's Birthday/Summer Solstice Challenge
PrimeGrid's Challenge Series continues with the "Birthday/Summer Solstice Challenge". Come join us as we celebrate PrimeGrid's 5th birthday. A 5 day Challenge is being offered on The Riesel Problem (Sieve) application. The celebration will culminate on 21 June, the Summer Solstice. For more information, please see this forum post. 4 Jun 2010 | 1:55:53 UTC · Comment


Server software upgrade
Server software has been upgraded to the latest version. It brings serveral improvements, mostly visible one probably is news forum where you can comment directly on news items.

However, as with every upgrade, there might be something that breaks, so in case you find anything not working or working not like it did previously, and you think that it's a bug, please report it in the comments for this newspost. Thanks!
11 May 2010 | 19:08:55 UTC · Comment


200M Cobblestones
Congratulations to SETI.Germany, the first team to reach 100M cobblestones at PrimeGrid...doubling their 100M cobblestone achievement in just over 9 months!!! :) 2 May 2010 | 2:00:00 UTC · Comment


Mega Prime for 321 Prime Search
Finally!!! A significant find during a Challenge. :) On 24 Apr 2010 11:40:07 UTC, PrimeGrid's 321 Prime Search found another Mega Prime:
3*2^6090515-1
The prime is 1,833,429 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 17th overall. This is the second mega prime for the 3*2^n-1 form, and it is the third largest found mega-digit prime using LLR. The discovery was made by David Mumper (Mumps) of the United States using an AMD Quad-Core Opteron 2378 with 8 GB RAM running Linux. This computer took just over 15 hours 24 minutes to complete the primality test. David is a member of the SETI.USA team. Official announcement and decimal representation of the prime.
26 Apr 2010 | 5:10:00 UTC · Comment


Earth Day Challenge
Turn the turbines into the wind and the solar panels towards the sun because in less than 13 hours, the Earth Day Challenge will begin. :) Come join us for an Earth Day (22 April) + 7 day Challenge on the 321 Prime Search (LLR) application. Even if you are not able to access "green" energy, check out the Earth Day discussion thread on other ways to offset your Challenge power consumption. For more information, please see this forum post. 22 Apr 2010 | 5:10:00 UTC · Comment


Earth Day Challenge
Earth Day is less than a week away. Hopefully the wind turbines are spinning and the solar panels are soaking up the sunlight. Come join us for an Earth Day (22 April) + 7 day Challenge on the 321 Prime Search (LLR) application. Even if you are not able to access "green" energy, check out the Earth Day discussion thread on other ways to offset your Challenge power consumption. For more information, please see this forum post. 16 Apr 2010 | 2:30:00 UTC · Comment


First ever AP26 Found!
The search is over. A World Record AP26 (Arithmetic Progression of 26 primes) has been found. The finder is Beno&#227t Perichon [AF>HFR>RR] Jim PROFIT) of France. He is a member of the L'Alliance Francophone team. The AP26 progression is written as 43142746595714191+23681770*23#*n for n=0..25. It was found by a PS3 running Linux. For more details on this find, please see this forum post. Congratulations to everyone who participated in the AP26 Search. It has been a very challenging and rewarding project. Also, a special thanks to all the programmers who ported AP26 making it the most accessible project at PrimeGrid.<br /><br /> Note: there will be no more work once the queue is empty, so we would like to ask people not running for the badges to stop running AP26 subproject and give a chance for others to reach their final levels. 12 Apr 2010 | 23:55:00 UTC · Comment


Earth Day Challenge
Earth Day is approaching so grab a couple of wind turbines and some solar panels and come join us for an Earth Day Challenge. Starting 22 April 2010, Earth Day, PrimeGrid will continue its Challenge series with an Earth Day + 7 day Challenge on the 321 Prime Search (LLR) application. Even if you are not able to access "green" energy, check out the Earth Day discussion thread on other ways to offset your Challenge power consumption. That way you can "have your cake, and eat it too!" :D For more information, please see this forum post. 8 Apr 2010 | 20:35:00 UTC · Comment


PRPNet's Fool's Day Mini Challenge
PrimeGrid is stress testing the PRPNet software today in a PRPNet Fool's Day Mini Challenge. Why 2 April and not 1 April...because 2 is the first prime number. :) The initial stress test will last for 24 hours and start 2 April 2010 18:00 UTC. If all goes well, there will be an extended stress test that will last until 9 April 2010 18:00 UTC. If you have the time and energy, please stop by if even for just a little while. For more details, please see this forum post. 2 Apr 2010 | 15:35:00 UTC · Comment


Record AP25 Found
A new record AP25 (Arithmetic Progression of 25 primes) has been found. It is the largest known AP25 and the 15th discovered. It has an ending term of 183651856404750473 surpassing the previous record of 178450656331295477. The finder is Chris Wingate (skinny9699) of the United States. He is a member of the Ubuntu Linux team. The AP25 progression is written as 18626565939034793+30821486*23#*n for n=0..24. It was found in the AP26 Search by an NVIDIA GeForce GTX 285 on an AMD Phenom 9750 running Linux. For more details on this find and the AP26 search, please see this forum post. 2 Apr 2010 | 15:15:00 UTC · Comment


The Ides of March Challenge
"Et tu, Brute?" Yes, even Brutus stopped by and took down a few k/n pairs. He and the rest of the "senators" did the dirty work of rounding up over 400 prime wannabe's and placing them forever in the realm of composites. While they won't make the same notoriety as Caesar did, they will still rest in peace. The results are final. Just over 1.01P was sieved in the 24 hours of the Challenge...an astounding amount of work done. Congratulations to SETI.USA as the top team and Shanky as the top individual. Thank you to everyone who participated!!! For more stats and information, please see this forum post. 17 Mar 2010 | 2:00:00 UTC · Comment


The Ides of March Challenge
The k/n pairs in the sieve file have been warned against a great peril on the Ides of March. Yet they arrogantly hang around hoping to be proven prime. Well, in less than 24 hours, that hope will be replaced with sheer fright. Please come join us as an honorary "senator" and help bring some k/n pairs to their demise. A 24 hour (15-16 Mar) Challenge is being offered on PrimeGrid's Prime Sierpinski Project/Seventeen or Bust (Sieve) application. For more information, please see this forum post. 14 Mar 2010 | 19:00:00 UTC · Comment


Record AP25 Found
A new record AP25 (Arithmetic Progression of 25 primes) has been found. It is the largest known AP25 and the 14th discovered. It has an ending term of 178450656331295477 surpassing the previous record of 144822829106549969. The finder is Dave Sunderland (DaveSun) of the United States. The AP25 progression is written as 25300381597038677+28603610*23#*n for n=0..24. It was found in the AP26 Search by an Intel Pentium 4 3.20GHz running 32 bit Windows XP Professional. For more details on this find and the AP26 search, please see this forum post. 14 Mar 2010 | 7:45:00 UTC · Comment


The Ides of March Challenge
Less than one week till it's the end for some prime wannabe's. A 24 hour (15-16 March) Challenge is being offered on PrimeGrid's Prime Sierpinski Project/Seventeen or Bust (Sieve) application. Come join us as we quicken the demise for some unlucky k/n pairs. Application builds are available for MacIntel, Linux, and Windows - with a 64 bit advantage. For more information, please see this forum post. 9 Mar 2010 | 14:15:00 UTC · Comment


Tour de Primes 2010 has ended!!!
A very productive month for the Tour de Primes. 309 "Top 5000" primes were discovered, easily surpassing last year's mark of 212. lennart SM5YMT of Sweden and the PrimeSearchTeam once again topped the leader boards winning his second yellow jersey in a row. He also picked up the green jersey for the first time. [SG]marodeur6 of Germany and team SETI.Germany takes home the checkered jersey. For more details about the tour and complete standings, please see this forum post. 1 Mar 2010 | 21:35:00 UTC · Comment


BEWARE the Ides of March!!!
PrimeGrid's Challenge series continues with the Ides of March Challenge. Once again we observe Caesar's demise by finding factors that will bring some k/n pairs to their demise. A 24 hour (15-16 March) Challenge is being offered on PrimeGrid's Prime Sierpinski Project/Seventeen or Bust (Sieve) application. For more information, please see this forum post. 1 Mar 2010 | 20:40:00 UTC · Comment


New AP25 Found
A new AP25 (Arithmetic Progression of 25 primes) has been found. It is the 13th discovered. The finder is Keith Pattenden ([url=http://www.primegrid.com/show_user.php?userid= 18217]KWSN - Sir Brian - err sorry - wrong film![/url]) of the United Kingdom. He is a member of the The Knights Who Say Ni! team. The AP25 progression is written as 42592855872841649+19093314*23#*n for n=0..24. It was found by an NVIDIA GeForce GTX 260 in an Intel Core2 Quad 6600 @ 2.40GHz running 32 bit Windows XP Professional. For more details on this find and the AP26 search, please see this forum post. 25 Feb 2010 | 13:00:00 UTC · Comment


New AP25 Found
A new AP25 (Arithmetic Progression of 25 primes) has been found. It is the 12th discovered. The finder is Bryan Little (mfl0p) of the United States. He is a member of the [H]ard|OC team. The AP25 progression is written as 58555890166091939+10416756*23#*n for n=0..24. It was found by an NVIDIA GeForce GTX 260 in an Intel Core2 Quad @ 2.40GHz running Linux. For more details on this find and the AP26 search, please see this forum post. 24 Feb 2010 | 19:30:00 UTC · Comment


The Year of the Tiger Challenge
The results are final. Cupid and the Tiger ravaged the primes - bringing in an unprecedented 110 "new" primes to the Prime Pages with over half of those making it into the Top 1000. Over 2M tasks (1M WU's) were completed resulting in over 23M cobblestones awarded...an astounding amount of work done for an LLR Challenge. Congratulations to SETI.USA as the top team and Mr. Hankey as the top individual. Thank you to everyone who participated!!! For more stats and information, please see this forum post. 23 Feb 2010 | 14:50:00 UTC · Comment


Planned maintenance
We will be doing software upgrades on the servers in the upcoming few hours that might make the website temporarily inaccessible. We will update this post when the updates are complete. <br /><br /> Update 14:05 UTC: maintenance has been completed successfully.<br /> Update 15:07 UTC: turns out database is misbehaving, so we need to extend the outage.<br /> Update 17:00 UTC: it seems that everything is running fine. 21 Feb 2010 | 11:45:00 UTC · Comment


The Year of the Tiger Challenge
Less than 4 hours remain. The hunt has been very successful for Cupid and the Tiger. Just as PrimeGrid's validator is struggling to keep up with the Challenge, the Prime Pages' validator is struggling to keep up with the prime submissions. :D Over 75 "Top 5000" primes have been found so far!!! There's still time to join the hunt. For more information, please see this forum thread. 17 Feb 2010 | 14:10:00 UTC · Comment


The Year of the Tiger Challenge
24 hours into the Challenge and Cupid and the tiger have been very successful in their hunt for primes - already snagging over 35 "Top 5000" primes. 48 hours remain so it's not too late to jump in the fray and see if you too can capture a prime. For more information, please see this forum thread. 15 Feb 2010 | 18:00:00 UTC · Comment


The Year of the Tiger Challenge
Only 24 hours remain till the start of the 2010 Challenge Series and Valentine's Day in the West and the Year of the Tiger in the East. Cupid is flying overhead while the tiger circles below. Please come join us in an East & West fearless attack on Proth Primes. A 3 day (14-17 Feb) Challenge is being offered on PrimeGrid's Proth Prime Search (LLR). Application builds are available for Mac, Linux, and Windows. For more information, please see this forum thread. 13 Feb 2010 | 18:00:00 UTC · Comment


The Year of the Tiger Challenge
One week till the start of the 2010 Challenge Series with the Year of the Tiger. A 3 day (14-17 Feb) Challenge is being offered on PrimeGrid's Proth Prime Search (LLR). Come join us as we stalk the primes. Application builds are available for Mac, Linux, and Windows. For more information, please see this forum thread. 7 Feb 2010 | 14:50:00 UTC · Comment


The Year of the Tiger Challenge
We are kicking off the 2010 Challenge Series with the Year of the Tiger Challenge which just so happens to coincide with Valentine's Day in the West. The Tiger is the third sign in the Chinese Zodiac cycle, and it is a sign of fearlessness. It is considered incredibly brave, evidenced by its willingness to engage in battle. So whether it's your love of Tigers or love of primes, please come join us in an East & West fearless attack on Proth Primes. A 3 day (14-17 Feb) Challenge is being offered on PrimeGrid's Proth Prime Search (LLR). Builds are available for Mac, Linux, and Windows. For more information, please see this forum thread. 3 Feb 2010 | 2:30:00 UTC · Comment


New AP25 Found
A new AP25 (Arithmetic Progression of 25 primes) has been found. It is the 11th discovered. The finder is Jan Stenzel (Jan Stenzel) of Poland. He is a member of the BOINC@Poland team. The AP25 progression is written as 49644063847333931+7851809 *23#*n for n=0..24. It was found by an Intel Core i7 860 @ 2.80GHz running 64 bit Windows 7. For more details on this find and the AP26 search, please see this forum post. 2 Feb 2010 | 4:20:00 UTC · Comment


Tour de Primes 2010
The Tour de Primes begins. Come join us in laid-back competition in tribute to the number 2...the first prime and the only even prime. The prizes are simple colored jerseys . Yellow for the most primes, Green for the highest prime score, and Checkered for the most primes on 17 Feb. No pressure or stress other than what you put on yourself. :) For more information, please see Tour de Primes 2010. 1 Feb 2010 | 0:00:00 UTC · Comment


Seventeen or Bust
On the eve of the Tour de Primes 2010, we are happy to announce that PrimeGrid is partnering with Seventeen or Bust to help solve the Sierpinski problem! This finally brings PrimeGrid full circle with SoB/PSP primality testing as well as combined sieving. Special thanks to Louis Helm of Seventeen or Bust for helping to make this collaboration possible! For more details on the new search, please see this forum thread. 31 Jan 2010 | 17:30:00 UTC · Comment


Tour de Primes 2010
February is a couple of days away which means it's time for the Tour de Primes. 2 is the first prime number...and the only even one. Therefore, we have declared February, the 2nd month, as prime month. We're offering a small competition in tribute to this unique prime number. There are no points to be gained or awards to be won...just a simple colored jersey (Yellow, Green, and Checkered) at the end of the month. No pressure or stress other than what you put on yourself. :) For more information, please see Tour de Primes 2010. 30 Jan 2010 | 0:30:00 UTC · Comment


New AP25 Found
A new AP25 (Arithmetic Progression of 25 primes) has been found. It is only the 10th discovered. The finder is Gerrit Slomma (roadrunner_gs) of Germany. He is a member of the Special: Off-Topic team. The AP25 progression is written as 46428033558097831+12893265*23#*n for n=0..24. It was found by an Intel Core2 6400 @ 2.13GHz running Linux. For more details on this find and the AP26 search, please see this [url=http://www.primegrid.com/forum_thread.php?id=1246&nowrap=true# 20398]forum post[/url]. 15 Jan 2010 | 16:00:00 UTC · Comment


New AP25 Found
A new AP25 (Arithmetic Progression of 25 primes) has been found. It is only the 9th discovered. The finder is Dan Swearingen (endearingswan) of the United States. The AP25 progression is written as 24715375237181843+19071018*23#*n for n=0..24. It was found by an Intel Pentium 4 @ 3.00GHz running 32 bit Windows XP Professional. For more details on this find and the AP26 search, please see this forum post. 5 Jan 2010 | 15:35:00 UTC · Comment


Megabit Prime for 27121 Search
On 23 Dec 2009, PrimeGrid's PRPNet found a megabit prime: 27*2 2218064+1 The prime is 667,706 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 56th overall. The discovery was made by Honza Cholt (Honza) of the Czech Republic using a dual Intel Xeon @ 3.06GHz with 4GB RAM. This computer took 2 hours 38 minutes and 59 seconds to complete the primality test. Honza is a member of the team BOINC.SK For more details about this search, please see this forum thread. 26 Dec 2009 | 6:25:00 UTC · Comment


2009 Challenge Series
PrimeGrid's 2009 Challenge Series has concluded. Congratulations to SETI.Germany (repeat Champion) as the top team and j2satx as the top individual. They are the overall winners to PrimeGrid's 2009 Challenge Series. For a list of other top finishers, please see this forum thread. As always, thank you for your help and support. None of this is possible without YOU! :) Have a safe and happy Holiday season. See you next year for PrimeGrid's 2010 Challenge Series! 24 Dec 2009 | 7:40:00 UTC · Comment


The Winter Solstice Challenge
The Winter Solstice is here!!! And the results are final. But the night is far from dark. The solstice fires are brighter than ever as the final Challenge of 2009 also happens to be the most active Challenge to date. Over 970K WU's were completed resulting in over 34.4M cobblestones awarded...an astounding amount of work done. Although no AP26 was found, six new AP24's were found along with countless smaller ones. Congratulations to SETI.USA as the top team and Mr. Hankey as the top individual. For more stats and information, please see this forum post This concludes PrimeGrid's 2009 Challenge Series. Overall final results will be posted soon. Many thanks goes out to everyone who participated!!! We wish you a Happy Holidays and see you next year! 21 Dec 2009 | 21:00:00 UTC · Comment


The Winter Solstice Challenge
The Winter Solstice is in 3 hours...and so too is the conclusion of the Challenge. Now is the time to start preparing for the finale. Please remember to upload early and often. The server is going to get hit hard as the Challenge draws to an end. We will start to lower "max cache" to help with this. There continues to be a lot of close races so don't miss out on your completed WU's. Best of Luck in these last 3 hours. 21 Dec 2009 | 14:47:00 UTC · Comment


The Winter Solstice Challenge
Over half way through and the solstice fires are exceptionally bright. So far four new AP24's have been found. Also, there are several very close races in the individual category. The Winter Solstice is almost upon us. It is not too late to come join the Winter Festival and warm yourself by the fires. For more information on how to join, please see this forum thread. 20 Dec 2009 | 14:00:00 UTC · Comment


The Winter Solstice Challenge
Only 13 hours remain till the Winter Solstice Challenge. The pre-fires have a nice red glow, and we're expecting them to turn a deep blue once the Challenge begins. Who knows...by the end of the Challenge they may even become white hot. :) Please come join us in a Winter Festival that is sure warm you up. The top spots for the 2009 Challenge Series are up for grabs. A 3 day (72 hour) Challenge is being offered on PrimeGrid's AP26 Project. Builds are available for Mac, Linux, Windows, Solaris, Cell/BE Linux (Playstation 3), and for the first time, GPU-CUDA23 app. For more information on how to join, please see this forum thread. 18 Dec 2009 | 4:47:00 UTC · Comment


Record AP25 & AP24 Found
A new record AP25 (Arithmetic Progression of 25 primes) has been found. It is the largest known AP25 and only the 6th discovered. It has an ending term of 139751114244588403 surpassing the previous record of 52115444782777781. It also includes the largest known AP24 with an ending term of 139751114244588403 surpassing the previous record of 108936498476106241. The finder is Rune Nordb&oslash;e Skillingstad (runesk) of Norway. He is a member of Team Norway. The AP25 progression is written as 12353443596260323+23793841*23#*n for n=0..24. The AP24 progression is written as 12353443596260323+23793841*23#*n for n=1..24. It was found in the AP26 Search by an NVIDIA GeForce GTX 285 on an Intel i7 CPU 940 @ 2.93GHz running 32 bit Windows...the first significant AP found by a GPU!!! For more details on this find and the AP26 search, please see this forum post. 17 Dec 2009 | 4:40:00 UTC · Comment


The Winter Solstice Challenge
Just under 48 hours remain till the Winter Solstice Challenge. Please come join us in a Winter Festival that is sure to warm you up. If the run-up to the start is any indication, the solstice fires will be burning bright. As the team and individual rankings are so close, this Challenge will determine who takes home the 2009 Challenge Series top spot. A 3 day (72 hour) Challenge is being offered on PrimeGrid's AP26 Project. Builds are available for Mac, Linux, Windows, Solaris, Cell/BE Linux (Playstation 3), and for the first time, GPU-CUDA23 app. For more information on how to join, please see this forum thread. 16 Dec 2009 | 18:00:00 UTC · Comment


Megabit Prime for 12121 Search
On 4 Dec 2009, PrimeGrid, in collaboration with 12121 Search, found a megabit prime: 27*2 1902689-1 The prime is 572,768 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 76th overall. The discovery was made by Peter Kaiser (Puzzle-Peter) of Germany using a dual Intel Xeon X5472 @3.0GHz with 16GB RAM. This computer took 59 minutes and 17 seconds to complete the primality test. Peter is a member of the team SETI.Germany. For more details about this search, please see this forum thread. 13 Dec 2009 | 16:20:00 UTC · Comment


AP26 CUDA Application Released
Initial testing has gone well. Therefore, the AP26 CUDA application has been publicly released for 32 bit Windows (will run on 64 bit) and for 64 bit Linux. For more "important" information about the release, please see this forum thread. 10 Dec 2009 | 19:15:00 UTC · Comment


Possible issues because of GPU apps.
We are working on GPU apps now so you can expect some glitches in work distribution. 10 Dec 2009 | 17:30:00 UTC · Comment


World Record Generalized Woodall Prime
Those with triskaidekaphobia can rest at ease tonight!!! A generalized Woodall prime for base 13 has been discovered!!! The prime was found in PrimeGrid's PRPNet and is the largest known generalized Woodall prime:<br /> 563528*13563528-1 The prime is 627,745 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for generalized Woodall primes and 65th overall. It is the largest non-base 2/non-generalized Fermat prime ever found. The discovery was made by Lennart Vogel (lennart SM5YMT) of Sweden using an Intel Q6600 @ 2.4 GHz with 4 GB RAM. This computer took about 3 hours and 54 minutes to complete the probable prime test. It took just over 30 hours to prove primality. For more details, please see the official announcement. 9 Dec 2009 | 5:20:00 UTC · Comment


The Winter Solstice Challenge
PrimeGrid's Challenge series continues with the Winter Solstice Challenge. Please come join us in observing Nature's ending/beginning of a cycle...a Winter Festival to determine who will take home the 2009 Challenge Series top ranking. There is a tie in the team category and a very close race among the top 3 in the individual category. :) A 3 day (18-21 Dec) Challenge is being offered on PrimeGrid's AP26 Project. Builds are available for Mac, Linux, Windows, Solaris, Cell/BE Linux (Playstation 3), and for the first time, possibly a GPU app. For more information, please see this forum thread. 4 Dec 2009 | 6:10:00 UTC · Comment


13 Gold Badges
Congratulations to Bruno Courty (bcoz) of France, PrimeGrid's first participant to achieve a GOLD badge in all 13 projects. This is quite a remarkable feat. A complete set of badges is a major milestone, but 13 GOLD badges is a phenomenal achievement. Bruno has been a participant at PrimeGrid since 27 Feb 2007 and is a member of the team L'Alliance Francophone. He is one of the lucky ones who received a TPS gold badge before the twin prime was found. Thank you to everyone participating. We hope to see many more achieve this milestone! 29 Nov 2009 | 21:45:00 UTC · Comment


Record AP25 Found
A new record AP25 (Arithmetic Progression of 25 primes) has been found. It is the largest known AP25 and only the 5th discovered. It has an ending term of 52115444782777781 surpassing the old record of 38271649410634609. The finder is Ian Dickinson (Vato) of the United Kingdom. He is a member of Team-Goobee.org. The progression is written as 46176957093163301+1109121*23#*n for n=0..24. It was found in the AP26 Search by an Intel Pentium III @ 1266MHz running 32 bit Linux!!! For more details on this find and the AP26 search, please see this forum post. 25 Nov 2009 | 0:35:00 UTC · Comment


The Giving Thanks Challenge
The results are final. Over 191K tasks were returned resulting in almost 575T completed for the PSP/SoB sieve. Congratulations to SETI.Germany as the top team and [XTBA>XTC] FRED as the top individual. In the overall Challenge Series standings, there is now a tie for the top spot between SETI.GERMANY and BOINCstats. There is also a tie for second in the individual rankings with [SG]marodeur6 and [XTBA>XTC] FRED. This sets the stage for an exciting finale in the Winter Solstice Challenge. Thank you to everyone who participated!!! For more stats and information, please see this forum post. 15 Nov 2009 | 23:00:00 UTC · Comment


Record AP24 Found
A new record AP24 (Arithmetic Progression of 24 primes) has been found. It is the largest known AP24. It has an ending term of 104710589416588949 surpassing the previous record of 98090802848850701. The finder is Roald Solbj&#248rg (Roald) of Norway. He is a member of Team Norway. The progression is written as 4891686128805269+19453568*23#*n for n=0..23. It was found by a PS3 in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 13 Nov 2009 | 14:20:00 UTC · Comment


The Giving Thanks Challenge
Less than 24 hours remain till the Giving Thanks Challenge. Come join us in a 1 day (24 hour) Challenge on PrimeGrid's Prime Sierpinski Project/Seventeen or Bust (Sieve) application. Please consider running a few PSP/SoB (Sieve) WU's before the Challenge begins so your client will already have the sieve file. This way, during the Challenge, bandwidth can be used to deliver WU's instead of the sieve file. :) Thank you! For more information, please see this forum thread. 12 Nov 2009 | 18:45:00 UTC · Comment


The Giving Thanks Challenge
PrimeGrid's Challenge series continues with the Giving Thanks Challenge. Please come join us in a celebration of PrimeGrid's users. In this season of giving thanks, we wish to thank you, the user, for another AMAZING year of crunching. A 24 hour (13-14 November) Challenge is being offered on PrimeGrid's Prime Sierpinski Problem/Seventeen or Bust (sieve) application. Builds are available for Mac, Linux and Windows. For more information, please see this forum thread. 11 Nov 2009 | 2:30:00 UTC · Comment


Generalized Fermat Prime Search
The Generalized Fermat Prime Search has been launched in PrimeGrid's PRPNet. This is a search for primes of the form b^2^n+1. They are named after Pierre de Fermat, considered to be one of the greatest French mathematicians of the seventeenth century. For more information, please visit this forum post. 10 Nov 2009 | 3:40:00 UTC · Comment


Record AP24 Found
A new record AP24 (Arithmetic Progression of 24 primes) has been found. It is the largest known AP24. It has an ending term of 98090802848850701 surpassing the old record of 93004136079654607. The finder is Marcus Rosario (Ritzgit) of the United States. He is a member of the Gay USA team. The progression is written as 4687877159107031+18203167*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 9 Nov 2009 | 5:20:00 UTC · Comment


Record AP24 Found
A new record AP24 (Arithmetic Progression of 24 primes) has been found. It is the largest known AP24. It has an ending term of 93004136079654607 surpassing the old record of 90769015637524109. The finder is Chris Wingate (skinny9699) of the United States. He is a member of the Ubuntu Linux team. The progression is written as 1948053460212667+17745794*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 5 Nov 2009 | 5:05:00 UTC · Comment


Record AP24 Found
A victory for the legacy systems!!! A new record AP24 (Arithmetic Progression of 24 primes) has been found. It is the largest known AP24. It has an ending term of 90769015637524109 surpassing the old record of 84418532426419063. The finder is Ian Dickinson (Vato) of the United Kingdom. He is a member of Team-Goobee.org. It was found by an Intel Pentium III @ 1266MHz running 32 bit Linux!!! The progression is written as 3634080452156039+16981607*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 1 Nov 2009 | 15:15:00 UTC · Comment


The Harvest Festival Challenge
The results are final. Over 1,490,000 tasks were completed by 200 teams and 1361 individuals resulting in over 100 new "Top 5000" primes. Congratulations to SETI.Germany as the top team and [SG]marodeur6 as the top individual. Many thanks goes out to everyone who participated!!! For more stats and information, please see this forum post. 10 Oct 2009 | 4:45:00 UTC · Comment


Record AP24's Found
Several new AP24's (Arithmetic Progression of 24 primes) have been found...two of which are records. They were found in the AP26 Search. For more details on these finds and the AP26 search, please see this forum thread. 10 Oct 2009 | 3:15:00 UTC · Comment


The Harvest Festival Challenge
PrimeGrid's Challenge series continues with the Harvest Festival Challenge. Please come join us in a Fall harvest of primes. A 48 hour (02-04 October) Challenge is being offered on PrimeGrid's Proth Prime Search (LLR) application. Builds are available for Linux, MacIntel and Windows. For more information, please see this forum thread. 28 Sep 2009 | 16:35:00 UTC · Comment


Unexpected outage
Today we experienced an unexpected outage lasting several hours. It was caused by database crash which has since been repaired. The server might be a little slow while it deals with work backlog, but all requests should go through eventually. We are very sorry for the inconvenience. 28 Sep 2009 | 14:20:00 UTC · Comment


Record AP24 Found
A new record AP24 (Arithmetic Progression of 24 primes) has been found. It is the largest known AP24. It has an ending term of 82761689028005821 surpassing the old record of 81531202836675089. The finder is Kevin Erickson (Kevin Erickson) of the United States. He is a member of the BOINCstats team. The progression is written as 10307159737232191+14120563*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 19 Sep 2009 | 0:15:00 UTC · Comment


Record AP25 Found
PrimeGrid has found a record AP25 (Arithmetic Progression of 25 primes). This is PrimeGrid’s third AP25 and only the fourth known. It has an ending term of 38271649410634609 surpassing the old record of 37814740008933889. The finder is Keith Dale ([url=http://www.primegrid.com/show_user.php?userid= 42470]GreenFish[/url]) of the United States. He is a member of team SETI.USA. The progression is written as 18162964758258289+3755664*23#*n for n=0..24. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 8 Sep 2009 | 4:45:00 UTC · Comment


Megadigit Probable Prime Found
Congratulations to Ben Maloney (paleseptember) who discovered the megadigit probable prime 2^4583176+2131. At 1,379,674 decimal digits, this is the first known probable prime with over a million digits. It should soon appear as the new probable prime record at the website of Henri and Renaud Lifchitz, PRP Records: Probable Primes Top 10000. Ben is participating in the project "Five or Bust" - The Dual Sierpinski Problem. This project is outside of PrimeGrid and can be located in the Mersenne forum. For additional information about this project, please see the Welcome to "Five or Bust!" thread. There are only 2 remaining sequences. To help with PRP testing, see this thread. To help with sieving, see this thread. 3 Sep 2009 | 0:00:00 UTC · Comment


Record AP25 Found
PrimeGrid has found a record AP25 (Arithmetic Progression of 25 primes). This is PrimeGrid’s second AP25 and only the third known. It has an ending term of 37814740008933889 surpassing the old record of 15523154536267043. The finder is Jochen Beck ([url=http://www.primegrid.com/show_user.php?userid= 25532]dh1saj[/url]) of Germany. He is a member of team SETI.Germany. The progression is written as 20919497549238289+3155495*23#*n for n=0..24. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 2 Sep 2009 | 14:40:00 UTC · Comment


Record AP24 Found
Another record AP24 (Arithmetic Progression of 24 primes) found by a PS3. It is the largest known AP24. It has an ending term of 81531202836675089 surpassing the old record of 60739320360456407. The finder is Bryan Little (mfl0p) of the United States. He is a member of the [H]ard|OCP team. The progression is written as 13678065943093049+13223804*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 25 Aug 2009 | 12:35:00 UTC · Comment


The Dog Days of Summer Challenge
The Dog Days are upon us! PrimeGrid's Challenge series continues with the Dog Days of Summer Challenge. Please come join us in ushering an end to the hot sweltering days of summer. A 5 day (18-23 August) Challenge is being offered on PrimeGrid's Woodall Prime Search (LLR)) application. Builds are available for Linux and Windows. For more information, please see this forum thread. 17 Aug 2009 | 12:10:00 UTC · Comment


Sophie Germain Prime Search
The long awaited debut of the Sophie Germain Prime Search has finally arrived. To participate, select Sophie Germain Prime Search (LLR) on your PrimeGrid preferences page. For more information, please see this forum post. 16 Aug 2009 | 15:55:00 UTC · Comment


A Request for Assistance
We are attempting to reach two BOINC users who have made significant prime discoveries at PrimeGrid. They are both active in other BOINC projects. Therefore, we would like to make a request to the entire BOINC community for help in finding these individuals. (KE7AAR) (UPDATE: Found) of the United States and team BOINC Synergy, shares credit for the World Record Twin Primes. (spinner@) of Japan and Team 2ch is the finder of the World Record Cullen Prime. If you have contact with either of these individuals, please have them check their BOINC emails or private messages in PrimeGrid's forum. Several attempts have already been made through these channels. Additionally, if you have any information that might help us in contacting these individuals, please contact us here: http://www.primegrid.com/contact.php <br /> (Update 2009-08-15 18:00 UTC) KE7AAR has been contacted, thanks to everyone for help! 14 Aug 2009 | 1:50:00 UTC · Comment


Cullen/Woodall Sieve
The Cullen/Woodall Sieve is active again. Both prime searches have reached n=7M in their primality testing. Therefore, combined sieving has begun on the next range of 10M PrimeGrid preferences[/url] page. 14 Aug 2009 | 1:40:00 UTC · Comment


50M Cobblestones for SG Grid!!!
Congratulations to SG Grid, for becoming the first single user account to reach 50M cobblestones at PrimeGrid. An outstanding and amazing accomplishment after being here for less than 8 months. 9 Aug 2009 | 14:40:00 UTC · Comment


World Record Twin Primes returned
The search is finally over!!! The Twin Primes have been discovered!!! Verification was quickly completed and the appropriate users are being contacted. Credit will be shared between the finder, top producer in terms of M, top producer in terms of primes found, and top siever. The Twin Primes were actually returned on the SAME!!! day as the Cullen Prime but were overlooked in the excitement of the Cullen. Work generation has been terminated so please select another project if TPS was your only project. The project will remain active until all outstanding work has been returned and credited. Stay tuned for more details. 6 Aug 2009 | 16:20:00 UTC · Comment


World Record Cullen Mega Prime found
On 25 Jul 2009 1:11:48 UTC, PrimeGrid's Cullen Prime Search found another World Record Cullen Mega Prime: 6679881&middot;26679881+1 The prime is 2,010,852 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 15th overall. It is the largest known Cullen prime and the largest found Mega Prime using LLR. This remarkable discovery comes less than 4 months after the last prime and is only the 16th known Cullen prime. Contact with PrimeGrid participant (spinner@) has not been returned. However, the participant is from Japan and is a member of Team 2ch. The prime was found using an Intel Xeon L5420 @ 2.50GHz with 6 GB RAM running Windows XP Professional. This computer took about 71 hours 58 minutes to complete the primality test. More details to come after contact is made. 5 Aug 2009 | 2:45:00 UTC · Comment


New AP24 Found
PrimeGrid has found a new AP24 (Arithmetic Progression of 24 primes)...the first by a PS3!!! The finder is Paolo Bassi ([FVG] bax) of Italy. He is a member of team BOINC.Italy. The progression is written as 25545151920212759+1140241*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 3 Aug 2009 | 17:05:00 UTC · Comment


World Record Cullen Mega Prime returned
As unbelievable as it may sound, another Cullen Mega Prime has been discovered!!! It is only the 16th known Cullen prime. It is also a top 15 prime at over 2M digits and the largest found by LLR. Additionally, it is PrimeGrid's largest prime to date. The discoverer is from Japan and a member of Team 2ch. Verification is in progress. Stay tuned for more details. 1 Aug 2009 | 15:40:00 UTC · Comment


New AP24 Found
PrimeGrid has found a new AP24 (Arithmetic Progression of 24 primes). The finder is Jeffrey D Sessler (Tostada) of the United States. He is a member of team Ars Technica. The progression is written as 20187352211709911+1799216*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 30 Jul 2009 | 14:10:00 UTC · Comment


New AP24's Found
While there were no AP24+ found during the Challenge, two AP24's actually were found in the hours leading up to the start. The finders are Andreas Mohr (andmore) of Germany and Tina Kent (Penguirl) of the United States. Andreas' progression is written as 19471368812966089+410682*23#*n for n=0..23 and Tina's progression is written as 20909681071069667+234797*23#*n for n=0..23. Both were found in the AP26 Search. For more details on these finds and the AP26 search, please see the following forum posts: Andreas' AP24 | Tina's AP24. 24 Jul 2009 | 18:35:00 UTC · Comment


100M Cobblestones
Congratulations to SETI.Germany, the first team to reach 100M cobblestones at PrimeGrid...doubling their 50M cobblestone achievement in only 5 1/2 months!!! Is 150M in their sights by year's end? We'll have to wait and see. Again, congratulations! :) 24 Jul 2009 | 14:40:00 UTC · Comment


Record AP24 Found
PrimeGrid has found a record AP24 (Arithmetic Progression of 24 primes). It is the largest known AP24. It has an ending term of 62869009767207037 surpassing the old record of 60739320360456407. The finder is Jan-Cornelius Molnar (janm) of Germany. The progression is written as 10317962076055027+10241601*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 19 Jul 2009 | 18:15:00 UTC · Comment


PlayStation3 application
We now have AP26 application for PlayStation 3. You may wish to check the forum thread in order to get it running at full speed. Thanks to mfl0p. 18 Jul 2009 | 18:35:00 UTC · Comment


Follow PrimeGrid on Twitter
For those of you using Twitter, you can now follow PrimeGrid and watch the progress of recent findings in the AP26 Search.<br /> PrimeGrid Twitter on Web: http://www.twitter.com/primegrid. Thanks to Lexs for implementing the updates script. 18 Jul 2009 | 18:30:00 UTC · Comment


New AP24 Found
PrimeGrid has found a new AP24 (Arithmetic Progression of 24 primes). The finder is Carsten Hartwig (SG Arsenic) of the United Kingdom. He is a member of the SETI.Germany team. The progression is written as 19516186145019209+313705*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 18 Jul 2009 | 2:05:00 UTC · Comment


The New Moon Challenge
PrimeGrid's Challenge Series continues with the New Moon Challenge. Please come join us in ushering in July's New Moon along with a new project to the Challenge Series. A 24 hour (21 July – 22 July) Challenge is being offered on PrimeGrid's AP26 (Arithmetic Progression of 26 primes) application. Builds are available for Linux, Mac, Windows, PS3, & Solaris. For more information, please see this forum thread. P.S. Also, the "most significant" Solar Eclipse this century is occuring on 22 July. :) See forum thread for more details. 14 Jul 2009 | 18:25:00 UTC · Comment


New AP24 Found
PrimeGrid has found a new AP24 (Arithmetic Progression of 24 primes). The finder is Bryan Little (mfl0p) of the United States. He is a member of the [H]ard|OCP team. The progression is written as 7979661543967237+9936237*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 12 Jul 2009 | 23:35:00 UTC · Comment


Record AP24 Found
PrimeGrid has found a record AP24 (Arithmetic Progression of 24 primes). It is the AP24 with smallest known start. It has a starting term of 39421708111691 decreasing the old record of 167806194923077. The finder is Mark Codding (Narwhal) of the United States. He is a member of Team Picard. The progression is written as 39421708111691+9740894*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 10 Jul 2009 | 14:15:00 UTC · Comment


New AP24 Found
PrimeGrid has found a new AP24 (Arithmetic Progression of 24 primes). The finder is Paweł Feruś (mindc) of Poland. He is a member of the BOINC@Poland team. The progression is written as 5531900872160491+9383796*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 6 Jul 2009 | 3:45:00 UTC · Comment


Record AP24 Found
PrimeGrid has found a record AP24 (Arithmetic Progression of 24 primes). It is the largest known AP24. It has an ending term of 60739320360456407 surpassing the old record of 60312982868878297. The finder is Carsten Hartwig (SG Arsenic) of the United Kingdom. He is a member of the SETI.Germany team. The progression is written as 13432401425380607+9219580*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 4 Jul 2009 | 13:25:00 UTC · Comment


AP26 application available for Solaris
We have released a version of AP26 application for 64bit Solaris (on AMD x86_64 or Intel EM64T CPUs, platform name x86_64-pc-solaris). This is our first application for this platform, which also makes AP26 an application that runs on the most platforms. Thanks to Gerrit Slomma for building the app!<br /> Psst... the PS3 version is coming ;) 1 Jul 2009 | 6:30:00 UTC · Comment


Record AP24 Found
PrimeGrid has found a record AP24 (Arithmetic Progression of 24 primes). It is the largest known AP24. It has an ending term of 60312982868878297 surpassing the old record of 25490711550130537. The finder is (AFXTBA Pitheque) of France. He is a member of the L'Alliance Francophone team. The progression is written as 14992521666441877+8832442*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 30 Jun 2009 | 19:50:00 UTC · Comment


New Top Host!
Congratulations to Worldwide Center of Mathematics, owner of the new top host at PrimeGrid. While this position has changed many times in the past, what makes this occasion unique is that this is the first time the top host is a Mac!!! EDIT: The above is in terms of RAC. In terms of total credit, UL1 holds a commanding lead of over 5M cobblestones with this host. 20 Jun 2009 | 2:05:00 UTC · Comment


The sieves have been Mac'd out!
321, PPS, and PSP sieves now have application support for Mac OS X 10.4 running on Intel and 10.5 running on 64bit Intel. PPS sieve also offers application support for Mac OS X 10.3 running on PPC. 15 Jun 2009 | 3:25:00 UTC · Comment


GIMPS does it again!!!
Congratulations to The Great Internet Mersenne Prime Search (GIMPS)! On April 12th, Odd Magnar Strindmo of Norway discovered the 47th known Mersenne prime, 2^42,643,801-1. It is the second largest known prime at 12,837,064 digits, only 141,125 digits smaller than the Mersenne prime found last August. The prime was independently verified June 12th. For more information, please visit the GIMPS site. Again, congratulations!!! 13 Jun 2009 | 4:20:00 UTC · Comment


PrimeGrid's Birthday/Summer Solstice Challenge
Just over 24 hours until the start of PrimeGrid's "Birthday/Summer Solstice Challenge". A 9 day Challenge is being offered on the Prime Sierpinski Problem (LLR) application. Long Challenge, long WU's, but the rewards are greater...250 Challenge points goes to the winner and should a prime be found, it will be a Mega Prime. For more information, please see this forum post. 11 Jun 2009 | 3:45:00 UTC · Comment


PrimeGrid's Birthday/Summer Solstice Challenge
PrimeGrid's Challenge Series continues with the "Birthday/Summer Solstice Challenge". A 9 day Challenge is being offered on the Prime Sierpinski Problem (LLR) application. We are celebrating PrimeGrid's 4th birthday on 12 June...culminating 21 June on the Summer Solstice. It seems fitting that the sun will shine the longest for the project with the longest WU. For more information, please see this forum post. 7 Jun 2009 | 6:30:00 UTC · Comment


Record APs Found
PrimeGrid has found two new records for AP22 and AP23 (Arithmetic Progression of 22 primes and 23 primes respectively). They are the smallest known starts for each of their classifications. The finders are Jacek Kotnowski (sosnahojna - team BOINC@Poland) of Poland for the AP22 record and Eric Markle (Nikodemus - team BOINCstats) of the United States for the AP23 record. They were found in the AP26 Search. For more details on these finds and the AP26 search, please see these forum posts - AP22, AP23. 29 May 2009 | 22:30:00 UTC · Comment


1,000,000,000 cobblestones for PrimeGrid!!!
Today, PrimeGrid surpasses the 1 Billion mark in cobblestones. From meager beginnings on 12 June 2005 to now, a tremendous amount of work has been accomplished...6 mega primes, 3 Fermat Number divisors, and over 4000 titanic primes have been discovered. Congratulation goes out to the entire community for an incredible achievement. Thank you all for your support! 20 May 2009 | 18:00:00 UTC · Comment


Scheduled downtime
We are going to have a one to two hour downtime tomorrow, May 18, at about 12:00 GMT, because the servers have to be moved to a different rack as the datacenter is upgrading their infrastructure. 17 May 2009 | 15:15:00 UTC · Comment


New Points Leader
Congratulations to SG Grid, for becoming the new points leader at PrimeGrid. What makes this accomplishment more amazing is that it was done in less than 5 months. The two projects that have benefited the most from this achievement are the Twin Prime Search and the Prime Sierpinski Problem. Again, congratulations! 15 May 2009 | 1:30:00 UTC · Comment


PrimeGrid mentioned at TEDx talk
Watch a TEDx Warwick talk by Francois Grey about citizen cyberscience, which also mentions PrimeGrid (at about 8:20) or download the video (215MB).<br /> $f("player", "/flowplayer/flowplayer-3.1.0.swf", { clip: { url: '/download/TEDx/francois_grey.flv', autoPlay: false } }); 13 May 2009 | 18:15:00 UTC · Comment


Mac OS X support!
We have released first PrimeGrid application for Mac OS X, Arithmetic Progression of 26 Primes Search (AP26). Mac OS X 10.3 running on PPC, 10.4 running on Intel and 64bit 10.5 running on Intel are supported.<br /><br /> Thanks to Iain Bethune for compiling the apps. 11 May 2009 | 9:00:00 UTC · Comment


Record AP24 Found
PrimeGrid has found a record AP24 (Arithmetic Progression of 24 primes). It is the largest known AP24 as well as the AP24 with smallest known start. The finder is Andreas Kobara ([url=http://www.primegrid.com/show_user.php?userid= 20289]Lexs[/url]) of Germany. He is a member of the Gentoo Linux Users Everywhere team. The progression is written as 167806194923077+4935146*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 6 May 2009 | 18:30:00 UTC · Comment


50M Cobblestones
Congratulations to L'Alliance Francophone, for reaching the 50M cobblestones level at PrimeGrid. They are only the second team to accomplish this. It actually occurred during the Showers to Flowers Challenge so this is a bit belated. Again, congratulations! 5 May 2009 | 0:15:00 UTC · Comment


The Showers to Flowers Challenge
The results are final. Over 1169T was crunched in the 48 hours of the Challenge and over 389,000 tasks were completed by 260 teams and 2092 individuals. Congratulations to SETI.Germany as the top team and [AF>XTBA>XTC] FRED as the top individual. Many thanks goes out to everyone who participated!!! For more stats and information, please see this forum post. 2 May 2009 | 14:00:00 UTC · Comment


The Showers to Flowers Challenge
Let the "rains" begin!!! The Showers to Flowers Challenge has started. A 2 day (48 hour) Challenge is being offered on PrimeGrid's Prime Sierpinski Project (Sieve) application. For more information, please see this forum post. 29 Apr 2009 | 18:00:00 UTC · Comment


The Showers to Flowers Challenge
Only 24 hours remain until it starts "raining" factors. A 2 day (48 hour) Challenge is being offered on PrimeGrid's Prime Sierpinski Project (Sieve) application. Come join us for a shower of factors in hopes to make those hidden primes bloom. :) For more information, please see this forum post. 28 Apr 2009 | 18:00:00 UTC · Comment


World Record Cullen Mega Prime found
On 20 Apr 2009 0:52:45 UTC, PrimeGrid's Cullen Prime Search found a World Record Cullen Mega Prime: 6328548*26328548+1 The prime is PrimeGrid's largest prime to date. It is 1,905,090 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 14th overall. It is the largest Cullen prime found and the largest found Mega Prime using LLR. The discovery was made by Dennis R. Gesker (Gesker) of the United States using an Intel Xeon E5420 @ 2.50GHz with 8GB RAM running Windows Server 2008. This computer took 32 hours 28 minutes to complete the primality test. For more details, please see the official announcement. Decimal representation of the number is also available. 21 Apr 2009 | 2:10:00 UTC · Comment


World Record Cullen Mega Prime found
A PrimeGrid participant has discovered a World Record Cullen Mega Prime in the Cullen Prime Search. This is a very special and rare find. It is only the 15th Cullen prime known. It is also a top 15 prime and the largest found by LLR. Additionally, it is PrimeGrid's largest prime to date. Stay tuned for more details. 20 Apr 2009 | 19:00:00 UTC · Comment


Record AP25 Found
PrimeGrid has found a record AP25 (Arithmetic Progression of 25 primes). This is PrimeGrid's first AP25 and only the second known. It is the largest AP25 having an ending term of 15523154536267043 surpassing the old record of 8132758706802551. It is also the AP25 with smallest known start 2960886048458003, the previous record being 6171054912832631. The finder is BOINC@Poland's "Super Computer" (SKB@P). It is a farm of machines funded by BOINC@Poland members. The progression is written as 2960886048458003+2346233*23#*n for n=0..24. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 9 Apr 2009 | 16:15:00 UTC · Comment


Record AP24 Found
PrimeGrid has found a record AP24 (Arithmetic Progression of 24 primes). It is the largest known AP24. It has an ending term of 19898154930924749 surpassing the old record of 19516877252820799. The finder is Pawel Stachowiak (stachu @ fiddex) of Poland. The progression is written as 7960592659339799+2326495*23#*n for n=0..23. It was found in the AP26 Search. For more details on this find and the AP26 search, please see this forum post. 7 Apr 2009 | 15:30:00 UTC · Comment


New AP24 Found
PrimeGrid has found a "New" Arithmetic Progression of 24 primes. The finder is Pawel Stachowiak (stachu @ fiddex) of Poland. The progression is written as 6274259724784693+2522655*23#*n for n=0..23. It was found in the AP26 Search. We expect to find many more and even a few AP25's along the way to the goal of an AP26. For more details on this find and the AP26 search, please see this forum post. 5 Apr 2009 | 19:30:00 UTC · Comment


321 Prime Search finds a Mega Prime
On 3 Apr 2009 15:40:01 UTC, PrimeGrid's 321 Prime Search found another Mega Prime:<br />3*25082306+1<br />The prime is 1,529,928 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 15th overall. It is the 6th largest Proth prime found and the largest found Mega Prime using LLR. The discovery was made by Andy Brady (Andy Brady) of the United States using an Intel C2Q Q8200 @ 2.33GHz with 3GB RAM running Windows Vista. This computer took about 14 hours 7 minutes to complete the primality test. Andy is a member of the BOINCstats team. <br />For more details, please see the official announcement. Decimal representation of the number is also available. 5 Apr 2009 | 7:20:00 UTC · Comment


321 Prime Search finds a Mega Prime
A PrimeGrid participant has discovered a Mega Prime in the 321 Prime Search! We are currently GFN divisibility testing the prime as well as awaiting contact with the discoverer. It is a top 15 prime and the largest found by LLR. Stay tuned for more details. 4 Apr 2009 | 14:10:00 UTC · Comment


Fermat Number Divisor
Congratulations to Eric Embling (Eric E) of the United States, the discoverer of PrimeGrid's third Fermat Number divisor in the Proth Prime Search project: 659*2^617815+1 Divides F(617813). It is the 3rd found Fermat Number divisor of 2009 and 273rd overall. It is the 6th largest Fermat Number divisor in Chris Caldwell's The Largest Known Primes Database. Incidentally, it is a new record for "weighted" Fermat Number divisors. For more information, please see this forum post. 2 Apr 2009 | 1:30:00 UTC · Comment


New AP24 Found
PrimeGrid has found a "New" Arithmetic Progression of 24 primes. The finder is Krzysztof Koczubik (ksysju) of Poland. This is his second AP24 discovery. The progression is written as 6872932294461509+2042703*23#*n for n=0..23. It was found in the AP26 Search. We expect to find many more and even a few AP25's along the way to the goal of an AP26. For more details on this find and the AP26 search, please see this forum post. 28 Mar 2009 | 5:40:00 UTC · Comment


The Ides of March Challenge
The results are final. Over 550,000 tasks were completed by 148 teams and 901 individuals. Congratulations to BOINCstats as the top team and j2satx as the top individual. Many thanks goes out to everyone who participated!!! For more stats and information, please see this forum post. 20 Mar 2009 | 4:50:00 UTC · Comment


The Ides of March Challenge
The photo finish is in and it looks pretty clear that BOINCstats has taken the team standings and j2satx the individual standings (unofficial). What an incredible past 24 hours. Job well done everyone!!! Congratulations all around. As for the fate of the primes, you can still hear their sorrowful moans as they are hauled off to the Top 5000 list. More details to come. 16 Mar 2009 | 18:35:00 UTC · Comment


The Ides of March Challenge
Just under 1 & 1/2 hours remain. So far, a week's worth of primes have been found in less than 24 hours...with more still coming in. The team and individual competitions are still battling it out. A photo finish seems inevitable. Now is the time to start preparing for the conclusion. Update your clients early and update often. For more information, please see this forum post. 16 Mar 2009 | 16:35:00 UTC · Comment


The Ides of March Challenge
8 hours into the Challenge and the primes are beginning to fall. The start went exceptionally well with over 40K tasks going out in 30 minutes (11630 tasks in the first 5 minutes)!!! Well done everyone. The team and individual competitions are heating up with fierce battles going on for the top spots. Looks like it's shaping up for another "down to the wire" finish. For more information, please see this forum post. 16 Mar 2009 | 2:10:00 UTC · Comment


The Ides of March Challenge
T-minus 18 hours and counting. The sievers have the primes on the run. The Ides of March approaches and doom is in the air for these primes. Come join us for a 24 hour Challenge on the Proth Prime Search LLR project. For more information, please see this forum post. 15 Mar 2009 | 0:00:00 UTC · Comment


GCW13 Mini-Challenge
Friday the 13th has come and gone. Sadly, those elusive and unique GCW13 primes continue to elude us. Looks like Friday, November the 13th will get its chance at finding them. However, the results will be much different in just over a day and a half from now for The Ides of March Challenge. The question isn't will a prime be found...it's how many. In a tribute to the sievers, come join us for a 24 hour Challenge on the Proth Prime Search LLR project. For more information, please see this forum post. 14 Mar 2009 | 2:00:00 UTC · Comment


GCW13 Mini-Challenge
Friday, March the 13th is HERE!!! And still no sighting of the elusive Generalized Cullen or Woodall base 13 primes. Will today be the day, or will we have to wait until Friday, November the 13th? Come join for a final push today. For more information, please see this forum post. 13 Mar 2009 | 1:25:00 UTC · Comment


GCW13 Mini-Challenge
Friday, March the 13th, is approaching which means it's time for another "friendly" mini-challenge to find a Generalized Cullen or Woodall base 13 prime. As we discovered last time, this is no easy task. With St. Patrick's day around the corner, we'll need a little bit of that Irish Luck to come early. :) For more information, please see this forum post. 9 Mar 2009 | 4:05:00 UTC · Comment


Fermat Number Divisor
Congratulations to Senji Yamashita (s-yama) of Japan, the discoverer of PrimeGrid's second Fermat Number divisor in the Proth Prime Search project: 519*2^567235+1 Divides Fermat F(567233). It is only the 2nd found Fermat Number divisor of 2009 and 272nd overall. It is the 7th largest Fermat Number divisor in Chris Caldwell's The Largest Known Primes Database. Incidentally, it is a new record for "weighted" Fermat Number divisors. For more information, please see this forum post. 7 Mar 2009 | 3:40:00 UTC · Comment


New AP24 Found
PrimeGrid has found a "New" Arithmetic Progression of 24 primes. The finder is Stefan Smietanowski (Blast) of Sweden. The progression is written as 2725131905640097+1342336*23#*n for n=0..23. This was found in the AP26 Search. We expect to find many more and even a few AP25's along the way to the goal of an AP26. For more details on this find and the AP26 search, please see this forum post. 6 Mar 2009 | 23:10:00 UTC · Comment


The Ides of March Challenge
The countdown has started, T minus 10 days and counting. The sievers are hard at work behind the scenes factoring out all the prime wannabe's. Doomsday is approaching the remaining candidates as there is little room left to hide. Come 15 March, GLORY will go to the finders and the primes will face their nemesis, the Top 5000 List at the Prime Pages. Be sure to catch some of that GLORY in the 24 hour Ides of March Challenge. For more information, please see this forum post. 5 Mar 2009 | 18:00:00 UTC · Comment


Statically-linked LLR wrapper
The new LLR wrapper that was released two weeks ago has now been updated to be fully statically-linked. Testing has gone well in the Proth Prime Search project. Therefore, it has been released for all LLR projects which include 321 Prime Search, Cullen Prime Search, Prime Sierpinski Problem, Twin Prime Search, and the Woodall Prime Search. 32 bit Linux support continues on ALL LLR projects. Again, thanks to Geoff Reynolds who has made this build a reality! 3 Mar 2009 | 19:30:00 UTC · Comment


BEWARE the Ides of March!!!
If you are a prime, BEWARE the Ides of March!!! Right now, 100's of sievers are working behind the scenes to clear the path for the primality testers to find you. And on 15 March, your time is up!!! A 24 hour Challenge is being offered on PrimeGrid's Proth Prime Search (LLR) application. For more information, please see this forum post. 2 Mar 2009 | 4:15:00 UTC · Comment


Tour de Primes 2009 has ended!!!
There were no surprise sprints on this last day...just a nice champagne stroll around the Champs-Elysées. Congratulations to the jersey winners: Yellow - Lennart; Green - s-yama; and Checkered - Lennart. For more details on the conclusion of the race, please see this forum post. 1 Mar 2009 | 6:55:00 UTC · Comment


New AP24 Found
PrimeGrid has found a "New" Arithmetic Progression of 24 primes. The finder is Krzysztof Koczubik of Poland. He is a member of BOINC@Poland. The progression is written as 13785500104035967+1004314*23#*n for n=0..23. This was found in the AP26 Search. We expect to find many more and even a few AP25's along the way to the goal of a record AP26. For more details on this find and the AP26 search, please see this forum post. 26 Feb 2009 | 17:45:00 UTC · Comment


321 Sieve
The 321 Sieve has completed its manual effort and is now available in BOINC. Current depth is p=2P for 5M PrimeGrid preferences[/url]and select 321 Prime Search (Sieve). It's currently available for Linux64 and Windows32/64. 19 Feb 2009 | 0:45:00 UTC · Comment


Tour de Primes 2009
Over half way through the Tour de Primes and Lennart continues to hold a comfortable lead. A quick look at his primes and you can see that he's taking advantage of PPSE on PRPNet. With the mountain stage coming up on the 23rd, it's not too late to reel him back in. For more information, please see Tour de Primes 2009. For information about PRPNet, please see this forum post. 18 Feb 2009 | 0:10:00 UTC · Comment


New LLR Wrapper for Linux
A new LLR wrapper for Linux has been released. Along with this release, there is now Linux support for the Cullen Prime Search (LLR) and Prime Sierpinski Problem (LLR). A special thanks to Geoff Reynolds, who made this build a reality! For more information, please see this forum post. 17 Feb 2009 | 22:25:00 UTC · Comment


12121 Prime Search
We are happy to announce that PrimeGrid is partnering with 12121 Search. Similar to 321 Search (k=3), 12121 Search is searching for single k primes of the form 121*2^n-1. They have been successfully searching since 2004 and are now in the Mega Prime area. For more details on the new search, please see this forum thread. 14 Feb 2009 | 4:10:00 UTC · Comment


Prime Month
The prime month competition is starting to heat up. Lennart has just recently broken away from the group and has a 3 prime lead. He has a mixture of BOINC and PRPNet primes. Is there anyone who can challenge him for the yellow jersey??? Just under 2/3's of the month remains so there's plenty of time for someone to rein him back into the peloton. For more information, please see this forum post. 10 Feb 2009 | 1:45:00 UTC · Comment


GCW13 Mini-Challenge
PrimeGrid user rogue has proposed a "friendly" mini-challenge to find a Generalized Cullen or Woodall base 13 prime on or before Friday, February 13th, 2009. A most ambitious endeavor! It will take the Luck of all the Irish PrimeGrid users for this prime to be found...especially on that date. However, to the finder goes all the spoils of fame (math fame) for these elusive gems! For more information, please see this forum thread. 9 Feb 2009 | 4:00:00 UTC · Comment


50M Cobblestones
Congratulations to SETI.Germany, the first team to reach 50M cobblestones at PrimeGrid. Also, a special thanks to pschoefer, SETI.Germany's administrator at PrimeGrid, who does an excellent job managing PrimeGrid's information for such a large team. Now the race is on for 100M cobblestones...can it be reached by year's end??? and by which team??? :) 8 Feb 2009 | 6:15:00 UTC · Comment


The Year of the Ox Challenge
While the Challenge is over, the Year of the Ox is just beginning. Over 18,000 321 WU's were completed by 133 teams and 589 individuals. Congratulations to BOINCstats as the top team and WilliamWallace as the top individual. It was a GREAT start to the 2009 Challenge Series. Congratulations to everyone and thank you for participating!!! For more information, please see this forum post. 31 Jan 2009 | 23:45:00 UTC · Comment


The Year of the Ox Challenge
24 hours into the Year of the Ox Challenge and all is well. In just this short time, BOINCstats has taken a commanding lead while the individual competition is a bit closer. It's not too late to join the fireworks in a celebration of the Chinese New Year. For more information, please see this forum thread. 27 Jan 2009 | 21:45:00 UTC · Comment


The Year of the Ox Challenge
Just over 24 hours remain until the Year of the Ox Challenge. Come join the fireworks in a celebration of the Chinese New Year, the Year of the Ox. A 5 day (26th-31st Jan) Challenge is scheduled on PrimeGrid's 321 Prime Search LLR application. For more information, please see this forum thread. 25 Jan 2009 | 15:15:00 UTC · Comment


The Year of the Ox Challenge
PrimeGrid's 2009 Challenge Series starts off with a fire cracker bang! Please come join us in the Chinese New Year, the Year of the Ox, for a 5 day (120 hour - 26th-31st Jan) Challenge on PrimeGrid's 321 Prime Search (LLR) application. The Ox is the sign of prosperity through fortitude and hard work. It is unswervingly patient, tireless in its work, and capable of enduring any amount of hardship without complaint. Sounds a lot like prime searchers. :) For more information, please see this forum thread. 20 Jan 2009 | 19:45:00 UTC · Comment


Norton Antivirus alarms
We are seeing multiple workunit failures and trouble reports because of Symantec (Norton) antivirus marking our screensaver as a probable virus. While there is nothing we can do about it, you can exclude BOINC data directory from antivirus path, and contact Symantec telling them about the false positive.<br /><br /> Please keep all discussions in this forum thread . 16 Jan 2009 | 15:00:00 UTC · Comment


First prime of 2009
Congratulations to zed, the discoverer of PrimeGrid's first prime for 2009 in the Proth Prime Search project: 15*2^483098+1. Unfortunately, it was just a double check. The first "new" prime of 2009 was found by Vato, again from the Proth Prime Search project: 835*2^483718+1. 1 Jan 2009 | 15:55:00 UTC · Comment


Fermat Divisor
Congratulations to Eric Ueda, the discoverer of PrimeGrid's first Fermat divisor in the Proth Prime Search project: 651*2^476632+1 Divides F(476624). It is only the 6th found Fermat divisor of 2008 and 270th overall. It is the 8th largest Fermat divisor in Chris Caldwell's The Largest Known Primes Database. For more information, please see this forum thread. 28 Dec 2008 | 18:45:00 UTC · Comment


AP26 Search
PrimeGrid has added a new prime search project, an Arithmetic Progression of 26 primes. An arithmetic progression of primes is a sequence of primes with a common difference between any two successive numbers in the sequence. For example 3, 7, 11 is an arithmetic progression of 3 primes with a common difference of 4. To participate, go to your PrimeGrid preferences page and select AP26 (currently only available for 64 bit Linux). For more information, please see this forum thread. 27 Dec 2008 | 18:50:00 UTC · Comment


Primorial Prime Search
PrimeGrid has added a new prime search project, the Primorial Prime Search. These primes are of the forms p#+1 and p#-1. It enters the Project Staging Area first as a manual sieving effort. Once sufficient depth has been reached, a primality testing effort will begin. For more information, please see this forum thread. 26 Dec 2008 | 7:00:00 UTC · Comment


2008 Challenge Series
PrimeGrid's 2008 Challenge Series has concluded. Congratulations to SETI.Germany as the top team and lennart SM5YMT as the top individual. They are the winners to PrimeGrid's inaugural 2008 Challenge Series. For a list of other top finishers, please see this forum thread. 24 Dec 2008 | 15:40:00 UTC · Comment


The Winter Solstice Challenge
The results are in for the Winter Solstice Challenge. Thank you for your patience. The margin of victory is 0.055%. Congratulations to WilliamWallace as the top individual and BOINCstats as the top team. For more information, please see this forum thread. The crowning of the top overall finishers in PrimeGrid's 2008 Challenge Series is next. 24 Dec 2008 | 1:10:00 UTC · Comment


The Winter Solstice Challenge
The Solstice has come and gone. Twas a tough last 12 hours but we have survived the night and the sun has risen again! The Winter Solstice Challenge ended with a tremendous battle. It's still too close to call. Thank you to all who participated in what turned out to be PrimeGrid's top Challenge of the Year. It would not have been possible without your support. For more information, please see this forum thread. Stay tuned...final results will be coming soon. 22 Dec 2008 | 6:50:00 UTC · Comment


The Winter Solstice Challenge
'tis but 12 hours left till the Solstice. The fire is burning bright and there's plenty of logs to keep it alit til the sun's return at dawn. :) The team and individual races are as tight as ever. It looks like this will go down to the wire. :) Thank you everyone for making this the most exciting Challenge yet. For more information, please see this forum thread. 21 Dec 2008 | 0:04:00 UTC · Comment


The Winter Solstice Challenge
Only 24 hours remain until the Winter Solstice...the longest night/shortest day of the year. Although we are in the middle of winter in the northern hemisphere, the competition remains very hot...not to mention the heat coming off the cores. :) This is by far the most highly contested Challenge of the year. Most fitting for the finale in the 2008 Challenge series. For more information, please see this forum thread. 20 Dec 2008 | 12:04:00 UTC · Comment


The Winter Solstice Challenge
Over 24 hours into the 4 day (96 hour) Challenge and all is well. Everything is going quite smooth right now. Another record breaking amount of work is being completed. There are some close races in both the team and individual categories. It's not too late to join in and give your favorite team a boost. :) For more information, please see this forum thread. 18 Dec 2008 | 18:50:00 UTC · Comment


The Winter Solstice Challenge
Less than 24 hours remain till the Winter Solstice Challenge. Come join us in a 4 day (96 hour) Challenge on PrimeGrid's Prime Sierpinski Project (Sieve) application. Please consider running a few PSP (Sieve) WU's before the Challenge begins so your client will already have the sieve file. This way, during the Challenge, bandwidth can be used to deliver WU's instead of the sieve file. :) Thank you! For more information, please see this forum thread. 16 Dec 2008 | 15:10:00 UTC · Comment


The Winter Solstice Challenge
PrimeGrid's Challenge series for 2008 ends with the Winter Solstice Challenge. Please come join us in observing Nature's ending/beginning of a cycle. A 4 day (96 hour) Challenge is being offered on PrimeGrid's Prime Sierpinski Project (Sieve) application. For more information, please see this forum thread. 10 Dec 2008 | 3:50:00 UTC · Comment


The Prime Time Challenge (Exploded)
The database has finally started to recover from the Challenge...and we have finished licking our wounds. It was one heck of an initiation for the new server. The one positive outcome is that an incredible amount of work was completed (over 3.3M results in 48 hours). Again, the participation greatly exceeded our expectations. Congratulations to SETI.Germany as the top team and zeitgeistmovie.com as the top individual. One new prime was found by Fish. Thank you to all who participated and especially for your patience. We very much appreciate the support. For more stats and information, please see this forum thread. 7 Dec 2008 | 4:20:00 UTC · Comment


The Prime Time Challenge (Reloaded)
Four and a half hours into the Prime Time Challenge (Reloaded) and all is well. After a few minor bumps at the start, everything seems to be going smoothly. Most definitely this is the highest activity PrimeGrid has ever seen. :) Finally a good initiation for the new server. Thank you to everyone participating. Now let's find some primes!!! For more information, please see this forum thread. 28 Nov 2008 | 22:30:00 UTC · Comment


The Prime Time Challenge (Reloaded)
The pre-stress on the server to the Prime Time Challenge (Reloaded) has shown a substantial improvement. A few more adjustments should make things even better. Therefore, the Challenge is on for 28 Nov - 30 Nov. More information can be found in this forum thread. 27 Nov 2008 | 19:00:00 UTC · Comment


The Proth Prime Search
The first new "reportable" primes have started to trickle in. Congratulations to Kai Strang for finding the first one 825*2^373331+1...just in time for the Prime Time Challenge (28 Nov - 30 Nov). Come join the Challenge and find a prime for yourself. For more information, please see this forum thread. 26 Nov 2008 | 15:45:00 UTC · Comment


The Prime Time Challenge (Reloaded)
The Prime Time Challenge has been rescheduled for 28 Nov - 30 Nov. We would like to pre-stress the server on 27 Nov at 17:00 UTC. For more information, please see this forum thread. 24 Nov 2008 | 17:20:00 UTC · Comment


The Prime Time Challenge
While the Challenge has been canceled (will be rescheduled) we will continue keeping stats for the current dates (14-16 November). The reason for this is that we want to continue to stress the server so we can see the impact on different server related issues. This will help us better prepare for the Prime Time Challenge (Reloaded). :) For those who are interested, please continue to crunch Proth Prime Search LLR through 16 Nov 2008 18:00 UTC. The results will be unofficial but the process will help us greatly. Thanks for the consideration and again, we apologize for the cancellation. 15 Nov 2008 | 17:15:00 UTC · Comment


The Prime Time Challenge has been canceled. While the server is fine, we are having issues that we are not yet able to resolve. We sincerely apologize for this. More information to come when we have it. 14 Nov 2008 | 21:00:00 UTC · Comment


The Prime Time Challenge
Less than 24 hours remain until the Prime Time Challenge (14-16 November 2008). The initiation process is already warming up as the load increases on the Proth Prime Search (LLR) in advance of the start. We are approaching the "reportable" level in Chris Caldwell's The Largest Known Primes Database! Come help us reach it and find a prime for yourself. For more information, please see this forum thread. 13 Nov 2008 | 18:00:00 UTC · Comment


The Prime Time Challenge
Less than a week remains until the 48hr Prime Time Challenge (14-16 November 2008). Come help us initiate the new server and maybe find a prime large enough to enter into Chris Caldwell's The Largest Known Primes Database! The Challenge will highlight PrimeGrid's newest project, the Proth Prime Search. For more information, please see this forum thread. 9 Nov 2008 | 4:30:00 UTC · Comment


Preparing for the Prime Time Challenge
The key to an effective prime search is having a good sieve file. For the past several months, our primary focus has been on getting the PPS Sieve deep enough to start LLRing. While we have made great strides in this effort, we still need more help. Leading up to this Challenge, anyone with a 64 bit multiple core system is encouraged to join the Proth Prime Search sieving effort. Please see this post if you are interested. 1 Nov 2008 | 3:30:00 UTC · Comment


The Prime Time Challenge
PrimeGrid's Challenge series continues with the Prime Time Challenge (14-16 November 2008). It's high time we initiated the new server and what better way to do it than with a Challenge. Also, it's time to return to the thrill of finding primes...and for that, we turn to PrimeGrid's newest project, the Proth Prime Search. Currently, these tests are rather short so this will also give us a good opportunity to "stress" test and fine tune the new server. The Proth Prime Search is slowly working its way up to the "reportable" prime level in Chris Caldwell's The Largest Known Primes Database! So please come join us as we initiate the new server and bring the Proth Prime Search to the "reportable" prime level. For more information, please see this forum thread. 31 Oct 2008 | 4:00:00 UTC · Comment


New server is live
While I'm writing these lines, the database is already running on the shiny new server in the new rack. While Murhpy has definitely played his role today, we hope that all troubles are gone and everything will be running smooth from now on.<br /><br /> The first minutes seem promising, and the speed has improved significantly. We'll keep you posted.<br /><br /> Big thanks for Willy for his work on the servers, and to all donators who helped make this server a reality! 27 Oct 2008 | 20:30:00 UTC · Comment


Scheduled downtime - new server installation!
We are planning a scheduled downtime of several hours on Monday, October 27. We will be relocating PrimeGrid and BOINCstats servers to the new rack, and will add a new server for PrimeGrid, which has been purchased using funds from the recent donation drive. 23 Oct 2008 | 18:10:00 UTC · Comment


"Optimal" sieve depth reached!
In a review yesterday of the Cullen/Woodall Project status, it was determined that we are at "optimal" sieve depth...actually, a little beyond it. Therefore, we are stopping the 32 bit and 64 bit Cullen/Woodall Sieve applications and archiving the sieve. Cullen/Woodall LLR will remain active up to n=10M. For more information, please see this forum post. 3 Oct 2008 | 16:50:00 UTC · Comment


Planned outage
We have just received a notice that the datacenter where PrimeGrid and BOINCstats are located are going to do planned maintenance on the electrical grid that is powering everything, so we will have an outage starting 23:00UTC. The outage is planned to last at least 3 hours. Sorry for the inconvenience; you may wish to cache a little more work this evening. 1 Oct 2008 | 17:15:00 UTC · Comment


10P milestone reached at PSP Sieve!
During the completion of the Challenge and in the excitement of reaching the funds for a new server, the Prime Sierpinski Problem Sieve entered into the 10P range. This was our "soft" goal for PrimeGrid's one year anniversary (13 October 2008). We reached it two weeks ahead of time. Congratulations everyone on this AMAZING accomplishment. For more information about the Prime Sierpinski Problem and next year's sieve goal, please see this forum post. 30 Sep 2008 | 15:05:00 UTC · Comment


A new server is in PrimeGrid's future!
The Back to the Future Challenge has ended. Over 8000 Woodall WU's were completed by 204 teams and 1108 individuals. Congratulations to BOINCstats as the top team and lunarcom as the top individual. Also, thanks to the help of the anonymous donor as well as the hundreds of users who participated in the Challenge, we now have the funds to purchase a new server. For more stats and information, please see this forum post. 29 Sep 2008 | 3:00:00 UTC · Comment


Message from Anonymous Donor
With just over half a day left in the Back to the Future Challenge, we have a solid green bar on the donation page. Congratulations everyone!!! The matching funds have come in as well as a message from the anonymous donor. A special thank you goes out to this individual for ensuring the continued growth of PrimeGrid. Best of Luck to everyone as this Challenge draws to an end. 27 Sep 2008 | 5:15:00 UTC · Comment


The Back to the Future Challenge
Less than three days remain in the Back to the Future Challenge. There's still a battle for the top spot with BOINCstats holding off a fierce charge by the Canadians! :) Does either team have something up their sleeves for the last 72 hours? Only time will tell. Overall the Challenge is going well. We are almost to n=5.4M with a goal of 5.5M in sight. Additionally, donations are still being accepted for the new server. Currently, with the matching funds from the private donor, we have reached our goal. Any additional funds will go towards upgrading the server specs. A special thank you to everyone for helping out. Best of Luck in the next 72 hours. 24 Sep 2008 | 19:45:00 UTC · Comment


The Back to the Future Challenge
Half way through and this is by far the most highly contested Challenge yet. Most surprisingly are the new teams and individuals atop the leader boards. A job well done by everyone. We are currently at the n=5.30M level with a goal of reaching 5.5M by the end. The Back to the Future Challenge has also made progress in donations for the new server. With seven days left, we have reached 52.8% of the funds needed. With the matching funds offer from the private donor, we need to reach at least 66.1%...the donor will complete the rest. One PrimeGrid user has started her own mini challenge, Krazy Kenzie's Server Challenge. She's just one donor away from success. :) Please check it out and see if you can help her make the "right" decision. 20 Sep 2008 | 18:00:00 UTC · Comment


GIMPS set to claim $100,000 EFF award!!!
Congratulations to The Great Internet Mersenne Prime Search (GIMPS)! On August 23rd, a UCLA computer discovered the 45th known Mersenne prime, 2^43,112,609-1, a mammoth 12,978,189 digit number! The prime number qualifies for the Electronic Frontier Foundation $100,000 award for discovery of the first 10 million digit prime number. By the way, the second prime discovered less than two weeks later was also more than 10 million digits. It's the the 46th known Mersenne prime, 2^37,156,667-1, and comes in at 11,185,272 digits. For more information, please visit the GIMPS site. 16 Sep 2008 | 16:30:00 UTC · Comment


45th and 46th Known Mersenne Primes Found!!!!
Congratulations to The Great Internet Mersenne Prime Search (GIMPS)! They have made extraordinary finds within two weeks of each other after going almost two years without a prime. We certainly marvel at this wonderful achievement. They are currently working on finding a suitable press outlet. More details will be announced early next week. The big question...is either one 10 million digits or more to claim the Electronic Frontier Foundation $100,000 award? :) For more information, please visit the GIMPS site. Again, congratulations!!! 12 Sep 2008 | 20:20:00 UTC · Comment


The Back to the Future Challenge
Less than 24 hours till the Back to the Future Challenge. Please come join us as we journey back to PrimeGrid's most successful project so far, the Woodall Prime Search, to help us prepare for the future. A private donor has made an anonymous "matching funds" offer matching all donations 1:1 made from now through the Challenge (13 Sept 18:00 UTC to 27 Sept 18:00 UTC) up to the total amount needed for the new server. For more information, please see this forum thread. 12 Sep 2008 | 19:40:00 UTC · Comment


The Back to the Future Challenge
PrimeGrid's Challenge series continues with the Back to the Future Challenge. We are very pleased and excited to announce that a private donor has made an anonymous "matching funds" offer. All donations made from now until the end of this Challenge (27 September) will be matched 1:1 (up to the total amount needed for the new server). Please come join us as we journey back to PrimeGrid's most successful project so far, the Woodall Prime Search, to help us prepare for the future. For more information, please see this forum thread. 6 Sep 2008 | 0:00:00 UTC · Comment


Prime for 321 Prime Search
We are still awaiting contact with the pre-Challenge 321 Prime Search prime finder. If no contact is made soon, the prime will be transferred over to anonymous. PrimeGrid user, LadyHawk_A321, please contact project administrator at admin@primegrid.com as soon as possible.<br /><br /> For more information on the prime, please see this forum thread. 31 Aug 2008 | 6:00:00 UTC · Comment


The Dog Days of Summer Challenge
Sirius has retreated to the horizon, but he refuses to go into the night sky without a prime. While the Challenge is over, the Dog Days remain...so let's put Sirius to sleep by finding that prime. It will take another 3-6 days for most results to be paired and declared valid. Therefore, Challenge rankings will not be finalized until then. The WU deadline was set to 3 days so unpaired results should be cleaned up quickly. For those who are interested in helping clean up these results, just leave your machines crunching 321 LLR for another 3 days. For up-to-date information, please see this forum thread. 25 Aug 2008 | 3:00:00 UTC · Comment


The Dog Days of Summer Challenge
Less than 24 hours remain. Sirius refuses to go back to the night. The only thing that is known to work is by feeding him a prime. So let's find that prime and bring the Dog Days of Summer to an end. :D For more information, please see this forum thread. 24 Aug 2008 | 4:00:00 UTC · Comment


Server down and back up
PrimeGrid server was inaccessible for about 30 minutes because the network at the datacenter where PrimeGrid and BOINCstats are hosted was down. The datacenter technicians seem to have brought the network back up, but we have no idea if it's going to stay up (the support phones of the hosting provider are down).<br /><br /> Update 18:11 UTC: it seems that the power was cut to the building; the servers were forcibly rebooted. I'm checking for stuck system processes now.<br /> Update 18:15 UTC: validator was stuck; it's fixed now. I think everything is running smooth now. 22 Aug 2008 | 17:55:00 UTC · Comment


The Dog Days of Summer Challenge
Less than 24 hours till the Dog Days of Summer Challenge . For more information, please see this forum thread. 21 Aug 2008 | 2:00:00 UTC · Comment


Prime for 321 Prime Search
The cooling rains have started early. In the run-up to the Dog Days of Summer Challenge, PrimeGrid's first 321 Prime Search prime has been discovered. Stay tuned for more details. UPDATE: 2008-08-18 We are still awaiting contact with prime finder. 16 Aug 2008 | 2:00:00 UTC · Comment


The Dog Days of Summer Challenge
Look yonder in the hot summer sky and you can see the clouds building. A storm is brewing in the distance...a storm to end the Dog Days of Summer. Please come join us in a 3 day (22-24 August - 72 hour) Challenge to usher an end to the hot sweltering days of summer. PrimeGrid's 321 Prime Search LLR application has been chosen. For more information, please see this forum thread. 15 Aug 2008 | 1:00:00 UTC · Comment


The Dog Days of Summer Challenge
PrimeGrid's Challenge series continues with the Dog Days of Summer Challenge. Please come join us in ushering an end to the hot sweltering days of summer. A 3 day (22-24 August - 72 hour) Challenge is being offered on PrimeGrid's 321 Prime Search LLR application. For more information, please see this forum thread. 8 Aug 2008 | 1:40:00 UTC · Comment


Riesel Sieve project information
For those of you wondering what is the problem with Riesel Sieve, here is a word from BOINC side administrator Bryan:<br /> <blockquote>Basically, the project creator has disappeared. People have been in contact with him, but we haven't heard any resumption date or even if things will resume. For the time being, I'm focusing my efforts on getting the non-BOINC side of the project up, as it is far easier and requires far less resources. We do not have access to any of the databases or we would have been able to restore things even without the project creator.</blockquote><br /> Our wishes for RS to return as soon as possible. 31 Jul 2008 | 16:00:00 UTC · Comment


PSP finds Mega Prime
The Prime Sierpinski Project has discovered their second mega prime: 258317*2^5450519+1. It is 1640776 digits long and will rank as the 12th largest known prime. The project has now found 17 primes total. There are only 12 primes left to solve the Prime Sierpinski Problem. For more information, please see this forum post. 27 Jul 2008 | 20:00:00 UTC · Comment


Back online
Database has been recovered, please read a lengthy explanation in this forum thread. 22 Jul 2008 | 6:20:00 UTC · Comment


Database issues
We are having database issues...stay tuned for more information. 21 Jul 2008 | 21:00:00 UTC · Comment


The Lunar Landing Challenge
"Houston, Tranquility Base here. The Eagle has landed." The Lunar Landing Challenge is over. Over 525,000 WU's were completed by 193 teams and 1331 individuals. Congratulations to SETI.Germany as the top team and Banshee as the top individual. For more stats and information, please see this forum post. 21 Jul 2008 | 14:45:00 UTC · Comment


The Lunar Landing Challenge
T-plus 24 hours after liftoff and all systems are nominal. :) The start severely stressed the vehicle, but it eventually made it into orbit. 48 hours remain until the Lunar Landing. For more information, please see this forum thread. 19 Jul 2008 | 0:00:00 UTC · Comment


The Lunar Landing Challenge
T-minus 10 hours till liftoff and all systems are go. A 3 day (18-20 July - 72 hour) Lunar Landing Challenge is being offered on PrimeGrid's Prime Sierpinski Project sieve application. For more information, please see this forum thread. 17 Jul 2008 | 14:00:00 UTC · Comment


The Lunar Landing Challenge
T-minus 3 days and counting. Unlike NASA, there are no holds in this countdown! :) Please come join us in commemorating the 39th Anniversary of the lunar landing by Apollo 11. A 3 day (18-20 July - 72 hour) Lunar Landing Challenge is being offered on PrimeGrid's Prime Sierpinski Project sieve application. For more information, please see this forum thread. 15 Jul 2008 | 0:00:00 UTC · Comment


WU's lengthened
PrimeGrid is experiencing an increase in activity. In order to minimize the database AND to prepare for the upcoming Lunar Landing Challenge, sieve WU's have been lengthened. Credit has been adjusted accordingly. For more information, please see this post. 14 Jul 2008 | 6:00:00 UTC · Comment


Database issues
We are having database issues, stay tuned for more information.<br /> Update 5:38 UTC: the database has been brought back online. 10 Jul 2008 | 5:25:00 UTC · Comment


Server software upgrade
[edit] Upgrade completed way ahead of schedule at 11:40 UTC.<br /><br /> I am upgrading server software, so the project is offline. Estimated time of upgrade completion - 13:00 UTC. After the upgrade is completed, I will update this newspost.<br /><br /> Post any issues you think may be caused by the upgrade to this thread. 7 Jul 2008 | 11:15:00 UTC · Comment


The Lunar Landing Challenge
PrimeGrid's Challenge series continues with the Lunar Landing Challenge. Please come join us in commemorating the 39th Anniversary of the lunar landing by Apollo 11. A 3 day (18-20 July - 72 hour) Challenge is being offered on PrimeGrid's Prime Sierpinski Project sieve application. For more information, please see this forum thread. 6 Jul 2008 | 14:00:00 UTC · Comment


3*2^n-1 switched to +1
We've switched 3*2^n-1 subproject, which has been completed to n=5M and had no more work, to 3*2^n+1. The tasks are significantly shorter now (in the range of minutes), but it will change quite rapidly as we progress through the test space. 29 Jun 2008 | 19:20:00 UTC · Comment


PrimeGrid's Birthday Challenge
The Birthday Party is over and all the candles have been blown out. Over 200,000 WU's were completed by 84 teams and 374 individuals. Congratulations to L'Alliance Francophone as the top team and Banshee as the top individual. For more stats and information, please see this forum post page. 13 Jun 2008 | 3:00:00 UTC · Comment


PrimeGrid's Birthday Challenge
Less than a day remains until the Birthday Challenge begins. We are celebrating PrimeGrid's 3rd Birthday with a 24 hour Challenge on the Twin Prime Search. Please check your local time zones to determine your exact Challenge time: 12 June 2008 00:00 UTC to 13 June 2008 00:00 UTC. For more information, please see this forum thread. 11 Jun 2008 | 3:30:00 UTC · Comment


PrimeGrid's Birthday Challenge
PrimeGrid's Challenge series continues with the Birthday Challenge. Please come join us in celebrating PrimeGrid's 3rd Birthday. A 24 hour Challenge is being offered on PrimeGrid's oldest active application, the Twin Prime Search. Hopefully we'll be able to give PrimeGrid a good present by finding the twin during the Challenge. :) For more information, please see this forum thread. 7 Jun 2008 | 14:15:00 UTC · Comment


The Drive for Five Challenge
The Checkered flag is out...and The Drive for Five Challenge has ended. 22512 WU's were completed by 255 teams and 1681 individuals. Congratulations to L'Alliance Francophone as the top team and Banshee as the top individual. Remember, the top 40 places earn points for this Challenge. For more stats and information, please see this forum post page. 1 Jun 2008 | 14:00:00 UTC · Comment


The Drive for Five Challenge
Less than 48 hours remain in the Challenge. For teams, places 1-4 are pretty much wrapped up. However, there is a tight 3-way battle for 5th place and several others beyond that. For individuals, there are many tight races below the top 3. Remember, due to the length of the Challenge, places 1-40 will earn Challenge Points this time. For more information, please see the Challenge Series page. 30 May 2008 | 1:30:00 UTC · Comment


The Drive for Five Challenge
Half way through the Challenge...and although an incredible amount of work has been accomplished, the numbers have the upper hand right now. 13020 WU's have been completed but 16036 remain. Our goal is still to reach n=5M. Therefore, we are hosting a sprint this weekend to see if we can get back even or maybe ahead of where we need to be in order to reach 5M by the end of 31 May. For more information, please see this forum post. 23 May 2008 | 12:00:00 UTC · Comment


The Drive for Five Challenge
24 hours into the Challenge and all is going well. 2100 WU's have been sent out and 26956 remain. Stats and more information can be found in this forum thread. 16 May 2008 | 0:30:00 UTC · Comment


The Drive for Five Challenge
Only 24 hours remain until The Drive for Five Challenge begins. Please check your local time zones to determine the start of the challenge: 15 May 2008 00:00 UTC. For more information, please see this forum thread. 14 May 2008 | 0:00:00 UTC · Comment


Updated application for TPS subproject - now has a screensaver!
New application version for TPS subproject has been released. If it behaves correctly, I will release it for other subprojects.<br /> For the first time, it also features a screensaver! 11 May 2008 | 14:10:00 UTC · Comment


The Drive for Five Challenge
PrimeGrid's Challenge series continues. Please come join our effort to reach n=5 million in the 321 Prime Search (3*2^n-1). The Challenge will begin 00:00 UTC, 15 May 2008. For more information, please see this forum thread. 9 May 2008 | 1:40:00 UTC · Comment


Problems saving preferences
We are aware of the issues saving your preferences (the message states that the changes have been saved, which doesn't actually happen), and are working to resolve the issue. It has been reported that logging out and in again helps, so you might try that as a workaround.<br /> UPDATE: as of 16:00 UTC preferences saving should work. 7 May 2008 | 15:45:00 UTC · Comment


Sieve WU lengths increased
In an attempt to lower the size of the database, we have increased the WU length to both the PSP Sieve and GCW Sieve projects. WU's are now 1.5X as long...so a 6 minute WU now takes 9 minutes. Credit has been adjusted accordingly. 30 Apr 2008 | 13:55:00 UTC · Comment


Workunit deadlines increased
The deadlines for subprojects that have very long workunits have been increased to 12 days. The subprojects affected are Woodall Prime Search, Cullen Prime Search, 321 Prime Search and Prime Sierpinski Project (all LLR). 26 Apr 2008 | 17:00:00 UTC · Comment


Standalone screensaver application published for testing
Nicolas has posted a standalone PrimeGrid screensaver application which is going to be included within the next science application update. We are looking for people to try it out on their computers so that we know it runs fine before we publish it project-wide.<br /><br /> Visit the thread in the forums to find more about it. 23 Apr 2008 | 20:00:00 UTC · Comment


Can you survive for 24 hours without your computer?
<br /> It is obvious that without computers we would find our life extremely difficult, maybe even impossible. If they disappeared for just one day, would we be able to cope?<br /><br /> Be part of one of the biggest global experiments ever to take place on the Internet. The idea behind Shutdown Day is to find out how many people can go without a computer for one whole day, and what will happen if we all participate!<br /><br /> Shutdown your computer on 03 May 2008 and find out! Visit shutdownday.org and join the campaign!<br /><br /> (And before you ask - no, PrimeGrid server isn't going down on that day) 23 Apr 2008 | 11:00:00 UTC · Comment


Mega Prime for 321 Search
On 23 Mar 2008 7:57:28 UTC, PrimeGrid, in collaboration with 321 Search, found another Mega Prime:<br /> 3*24235414-1<br /> The prime is 1,274,988 digits long and enters The Largest Known Primes Database ranked 14th overall. This is 321 Search's first mega prime and 11th prime overall. It is the second largest found mega-digit prime using LLR.<br /> The discovery was made by Dylan Bennett of Canada using an Intel C2D @ 1.66 GHz with 2GB RAM. This computer took almost 15 hours and 30 minutes to complete the primality test.<br /> For more details, please see the official announcement. Decimal representation of the number is also available. 18 Apr 2008 | 15:05:00 UTC · Comment


Mega Prime for 321 Search
A PrimeGrid participant has discovered a Mega Prime for the 321 Search project. Stay tuned for more details. 17 Apr 2008 | 1:40:00 UTC · Comment


Updated statistics for prime finders
We have released an updated prime finder statistics page, which now counts primes find in all subprojects. The prime numbers are assigned a score which differs according to prime number size, so a giant Woodall prime is "worth" more than a smaller TPS prime. <br />The next step in improving statistics is to show the participants all the primes that have been found, which isn't yet available in the current version, but is coming soon. 14 Apr 2008 | 18:30:00 UTC · Comment


Project Staging Area
After two months of testing, the Project Staging Area is officially open. This area was established to help prepare future projects for entry into PrimeGrid BOINC. It also offers a sneak peak into these projects by allowing users a chance to crunch them ahead of time. For more information, please see this forum thread. 14 Apr 2008 | 14:00:00 UTC · Comment


PSP finds Mega Prime
The Prime Sierpinski Project has discovered their first mega prime: 265711*2^4858008+1 (1462412 digits long). The project has now found 16 primes total. There are only 13 primes left to solve the Prime Sierpinski Problem. For more information, please see this forum thread. 10 Apr 2008 | 17:40:00 UTC · Comment


Up and running again
We are back up and running. For a detailed explanation of the events that caused the outage, please see the forum thread. 26 Mar 2008 | 19:00:00 UTC · Comment


PrimeGrid Database Issues
The aftermath of the Ides of March Challenge has taken its toll as the database has been experiencing issues since 20 March 2008. Conditions are slowly starting to improve. For more information, please see this forum thread. 22 Mar 2008 | 18:15:00 UTC · Comment


The Ides of March Challenge is Complete
Congratulations everyone on a job well done. The participation was well beyond our expectations. We exceeded our initial goal of 50K WU's and our advanced goal of 250K WU's downloaded. Additionally, we completed well beyond the sieve depth of p=2500T so a GREAT milestone for the Prime Sierpinski project and Seventeen or Bust. For more details on results, please see this forum post. 16 Mar 2008 | 4:00:00 UTC · Comment


The Ides of March Challenge Update
First 12 hours of the challenge have gone well! 186.1K WU's have been downloaded so far. Our original goal was 50K and that was hit 1 hour 35 minutes into the Challenge. Quite AMAZING!!! For an updated status, please see this forum post. 15 Mar 2008 | 12:00:00 UTC · Comment


The Ides of March Challenge Update
Less than 10 hours until the Ides of March. There has been an unprecedented run-up before the Challenge. We can sense the impending doom for 1000's of k/n pairs. For updated information, please see the forum thread. 14 Mar 2008 | 14:00:00 UTC · Comment


The Ides of March Challenge Update
Only 3 days remain until the Ides of March. Please check you local time zones to determine the start of the challenge: 15 March 2008 00:00 UTC. For updated information, please see the forum thread. 12 Mar 2008 | 15:00:00 UTC · Comment


The Ides of March Challenge
With the Ides of March just a week away, we wish to offer a challenge. Come join a one day effort in an attempt to push the Prime Sierpinski Sieve to over 50,000 WU's in one day and thus reach the p=2500T sieve depth. For more information, please see the forum thread. 8 Mar 2008 | 14:15:00 UTC · Comment


64bit Linux sr2sieve
A 64bit Linux sr2sieve application has been released for the Prime Sierpinski Problem sieve. For more information, please see the forum post. 2 Mar 2008 | 15:00:00 UTC · Comment


Upcoming Projects
PrimeGrid will soon be offering three new projects. For more information about these and future considerations, please see the forum thread. 27 Feb 2008 | 5:30:00 UTC · Comment


Problems with 64bit Windows PSP Sieve fixed
Version 1.04 of PSP Sieve application has been released, fixing the issue with 64bit Windows hosts. 20 Feb 2008 | 18:30:00 UTC · Comment


Problems with 64bit Windows PSP sieve application
We have temporarily disabled 64bit Windows PSP Sieve application because it was crashing and locking up BOINC client. We are investigating the cause for that; for now 32bit application will be sent instead. 19 Feb 2008 | 13:15:00 UTC · Comment


64bit Linux gcwsieve
I know some of you were eagerly awaiting this. Well, the time has come - we now started testing 64bit Linux gcwsieve application. For more information, see the forum thread. 18 Feb 2008 | 10:15:00 UTC · Comment


End of the life cycle of primegen application
We are inserting the final batches of work for our oldest available application, primegen. While primegen has proved to be very useful in the early project stages for infrastructure testing, it has served it's purpose and it's time to make way for newer, more efficient applications. Once the final batches are completed the cleanup will be executed, finally removing old stuck workunits. <br /><br /> We suggest participants running primegen exclusively also select an additional subproject for future processing. Sieve subprojects are very similar to primegen in size, so it is probably a good choice. Once there are no more primegen work to send, we will update project for such participants to select sieve subprojects. 15 Feb 2008 | 15:23:00 UTC · Comment


Unscheduled outage
PrimeGrid is down for a moment, because workunit table has crashed; the repair process is running right now. Thanks to Lennart from Sweden who called me on the phone and told about the problem.<br /> Update 14:22 UTC: We're back up. 31 Jan 2008 | 14:15:00 UTC · Comment


TPS work available again
Twin prime search work is available again (we had a few days outage for this subproject because work supply went dry). 10 Jan 2008 | 8:15:00 UTC · Comment


Record breaking Woodall prime
On 21 Dec 2007, 10:09:30 UTC, PrimeGrid's Woodall Prime Search found the 33rd and largest known to date Woodall prime:<br /> 3752948*23752948-1<br /> The prime is 1,129,757 digits long and enters The Largest Known Primes Database ranked 1st for Woodall primes and 13th overall. It's the first found mega-digit prime using LLR.<br /> The discovery was made by Matthew J. Thompson of the United States using an Intel P4 @ 2.8 GHz with 512MB RAM. This computer took almost 15 hours and 11 minutes to complete the primality test. 29 Dec 2007 | 21:05:00 UTC · Comment


1 million digit prime
A user of PrimeGrid has discovered a Woodall prime which is over 1 million digits long. It is the biggest Woodall prime ever discovered, and 13th biggest known prime of any kind. Stay tuned for more details. 28 Dec 2007 | 20:30:00 UTC · Comment


Code upgrade
Server backend code has been upgraded, the option to decline team founder transfer now works. If you notice any errors (no, dozens of buttons in the forum is not an error), please post in the forums or use the contact link available in every page in the very bottom. 16 Dec 2007 | 15:30:00 UTC · Comment


Scheduled downtime
During the night of December 14/15 (Europe time) PrimeGrid server will be down because of scheduled maintenance in the datacenter where PrimeGrid and BOINCstats are hosted. The downtime is needed to upgrade power infrastructure, because currently there isn't enough backup power (UPS) to run all the servers in case of a power outage. 9 Dec 2007 | 16:00:00 UTC · Comment


New subproject available
We have released the LLR application for the 321 Search. 321 is attempting to find a mega prime in the form 3*2^n-1. The 4+ year old project currently holds the largest non-GIMPS/non-Seventeen or Bust prime.<br /> As usual, you can choose to crunch work for this project by visiting your project preferences page. Supported platforms: 32bit Linux & Windows. 5 Dec 2007 | 17:45:00 UTC · Comment


Unexpected outage (resolved)
Results table has crashed, the project is offline while we recover data.<br /> Update: the issue has been resolved at 8:57 UTC. 5 Dec 2007 | 8:13:00 UTC · Comment


Automatic reporting to the Prime Pages available
From now on you can give permission to PrimeGrid to report the primes you find to the Prime Pages on your behalf. To do this, go to the project preferences page and enter your data. 30 Oct 2007 | 9:45:00 UTC · Comment


Backend code upgrade
The backend code has been upgraded. There were some issues related to the web code, but they seem to be fixed. If you find any problems that I missed, please post in the forums. 27 Oct 2007 | 20:00:00 UTC · Comment


Linux LLR available!
Good news for Linux lovers - with the help from our user Der Meister we have released 32bit Linux LLR application for Twin Prime Search project. If it goes well, it will be released for Cullen/Woodall Prime Search, too. The 32bit application is also being sent to 64bit hosts. 14 Oct 2007 | 12:15:00 UTC · Comment


Prime Sierpinski Project sieve available
We have released Sieve application for Prime Sierpinski Project. It is trying to solve the Prime Sierpinski Problem. Windows 32bit and 64bit versions are supported. As usual, you can choose to crunch work for this project by visiting your project preferences page. 13 Oct 2007 | 14:15:00 UTC · Comment


LLR Cullen percentage reporting bug fixed
Thanks to Bryan from Riesel Sieve, the Cullen workunit progress reporting bug has been fixed. The workunits running application version 5.08 should correctly display feedback during processing. 30 Sep 2007 | 16:15:00 UTC · Comment


64bit sieving application available
A 64bit Windows version of GCW sieve application has been released. It improves speed twice comparing to 32bit version. The new application is automatically sent to hosts running 64bit version of BOINC that have sieving subproject enabled in the project preferences. 29 Sep 2007 | 15:30:00 UTC · Comment


Cullen/Woodall Sieve available
We have released a sieving app for Cullen/Woodall Prime Search. Sieving will help to greatly reduce the amount of probable primes, therefore speeding up the actual prime search. You can choose to run sieve application by visiting project preferences page; please have in mind that the application has just been released, so it may have bugs or issues (although we haven't noticed any).<br /> Supported platforms: Windows 2000/XP/2003/Vista. 15 Sep 2007 | 18:35:00 UTC · Comment


Record Woodall prime number found... again!
On 20 Aug 2007, 2:40:57 UTC, PrimeGrid's servers returned a positive result in the Woodall Prime Search. It was the double check validating that a Woodall prime was found on 13 Aug 2007, 1:42:08 UTC. 2367906*22367906-1 This is the 32nd and largest known to date Woodall prime. It is 712818 digits long and enters The Largest Known Primes Database (http://primes.utm.edu/primes/) ranked 1st for Woodall primes and 25th overall.<br /><br /> The discovery was made by Stephen Kohlman of Canada using an Intel C2D 6300 @ 1.86 GHz with 1 GB RAM. This computer took a little over 5 hours and 41 minutes to test using the LLR program. Stephen is a member of Canada team. 3 Sep 2007 | 15:00:00 UTC · Comment


Leaving to Geneva
I will be leaving to Geneva for BOINC Workshop early tomorrow morning. This means that the project will have to run unattended for almost a week (I will of course monitor the server, but my time will be limited, so don't expect quick fixes if something dies). 3 Sep 2007 | 7:25:00 UTC · Comment


Message to participant "Owner"
Message to project participant known as "Owner" or "big steve": please contact project administrator at admin@primegrid.com. Your computer has made a significant discovery, and we want to know your details before we publicize it. 25 Aug 2007 | 15:15:00 UTC · Comment


Network maintenance
Tonight at 0:00UTC network maintenance will be performed in the datacenter where PrimeGrid server is hosted. The maintenance is planned to last approximately 30 minutes, during it the access to the project might be slow or unavailable. Sorry for the inconvenience. 19 Aug 2007 | 16:30:00 UTC · Comment


Record Woodall prime number found
On 7 Aug 2007, 15:25:07 UTC, PrimeGrid's servers returned a positive result in the Woodall Prime Search. It was the double check validating that a Woodall prime was found on 4 Aug 2007, 19:36:57 UTC.<br /> 2013992*22013992-1 The prime is 606279 digits long and enters The Largest Known Primes Database (http://primes.utm.edu/primes/) ranked 1st for Woodall primes and 37th overall.<br /><br /> The discovery was made by Lasse Mejling Andersen of Denmark using an Intel Celeron 2.80 GHz with 512 MB RAM. This machine took a little over 3 hours and 27 minutes to test using the LLR program.<br /><br /> For more details, please see here. 9 Aug 2007 | 18:00:00 UTC · Comment


Biggest ever Woodall prime discovered!
A few minutes ago PrimeGrid validated a workunit that had discovered the biggest Woodall prime ever discovered. More information will follow up later. 8 Aug 2007 | 5:56:00 UTC · Comment


Validation suspended
Validation of returned results may be slow or even temporarily suspended while we sort the problems that appeared because of software upgrade. All credit will be granted, no work is lost. 6 Aug 2007 | 12:20:00 UTC · Comment


Statistics moved
Stats sites should update references to PrimeGrid stats - filenames have changed because of recent code update. 4 Aug 2007 | 19:30:00 UTC · Comment


Maintenance extended
The maintenance has been extended because of issues getting new work. 3 Aug 2007 | 21:30:00 UTC · Comment


Shutdown for maintenance
PrimeGrid will be shut down for major software upgrade on August 3rd, 15:00UTC. The outage will last at least 4 hours, but may well be extended up to 48 hours. 2 Aug 2007 | 14:59:05 UTC · Comment


New subproject added
We have added a new prime search project, Cullen/Woodall prime search. These primes are of forms n*2n+1 and n*2n-1 respectively. Our goal is to find the biggest Cullen and Woodall primes ever. This isn't as easy as it may sound, only 14 Cullen primes and 30 Woodall primes have ever been found, however, we believe that PrimeGrid has sufficient computing power to make this search plausible.<br /><br /> It is now possible to choose the subprojects you would like to run in project preferences page. Please note that when you are using account managers your choice may be reset when changing resource share allocation. 3 Jul 2007 | 17:16:20 UTC · Comment


Twin Prime Search progress
Our user Terminal has been collecting statistics about our progress in the current Twin Prime Search project. Please see this thread for more information. 15 Jun 2007 | 14:02:48 UTC · Comment


10 million workunits sent
Today marks the day when 10 millionth workunit was issued in the project. While this is nothing more than a simple numeric milestone, it is a really nice number to reach in the project that is all about numbers.<br /><br /> The workunit was crunched by the computer owned by user Strelnieks. Congratulations! 6 Jun 2007 | 17:39:59 UTC · Comment




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