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JohnHonorary cruncher
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Joined: 21 Feb 06 Posts: 2875 ID: 2449 Credit: 2,681,934 RAC: 0

On 4 April, 2008, 22:22 UTC, the Prime Sierpinski Project discovered their first mega prime: 265711*2^4858008+1 (1462412 digits long). It was found on PSP's LLRNet by Scott Gilvey (Sloth) using an Intel C2D E4500 @ 2.2 GHz with 2 GB RAM. While PrimeGrid did not find the prime, we share credit because of the amount of work we have contributed. This prime would still be at least year or so away if not for our combined efforts now.
Additionally, just last week, we reached a major milestone with PSP sieve. PrimeGrid has now sieved more work than the combined efforts of the Seventeen or Bust (since 2003) and PSP (since 2004) manual sieves...and did it in less than 6 months. This is an incredible accomplishment earlier than expected in large part because of the success of the Ides of March Challenge. The speed in which this was achieved would never have been possible without your contributions.
A hearty thanks to everyone who participates in PrimeGrid and a big CONGRATULATIONS to the Prime Sierpinski Project.
Thank you from the PrimeGrid staff.

To participate in PSP, please visit your PrimeGrid preferences page and select either PSP sieve or PSP LLR. Additionally, you can visit the Prime Sierpinski Project and learn about how to contribute in a minimally more manual way.

As for the Prime Sierpinski Project, here are some more details.
PSP is attempting to solve the Prime Sierpinski Problem.
We look at a special class of prime numbers called proth numbers which have the general formula k*2^n+1. We further specialize our search by looking at numbers for which k is prime in k*2^n+1. Furthermore, it has been proven that there exists an infinite number of prime k's such that k*2^n+1 can never be prime. These k's are called prime sierpinski numbers.
The smallest proven prime sierpinski number is 271129. We are looking at all prime k's below this number and trying to prove that they are not sierpinski numbers and thus studying the distribution of primes of the forum k*2^n+1. The easiest way to prove that a k is not a prime sierpinski number is to find a prime for that k.
There are 13 candidates remaining for which we need to find a prime. PSP is searching for 10 of these while 3 others are part of the Seventeen or Bust project.
Here's a list of the remaining k's:
79309
79817
90527
152267
156511
168451
222113
225931
237019
258317
22699  SoB
67607  SoB
List of Primes already found!
10223*2^31172165+1 is prime! (found by SyP on 31 Oct 2016)
265711*2^4858008+1 is prime! (found by Sloth on 04 Apr 2008)
222361*2^2854840+1 is prime! (found by Shy24 on 31 Aug 2006)
214519*2^1929114+1 is prime! (found by ltd on 2 Jan 2006)
149183*2^1666957+1 is prime! (found by ltd on 7 Oct 2005)
241489*2^1365062+1 is prime! (found by Citrix on 25 Jan 2005)
216751*2^903792+1 is prime ! (found by ltd on 10 May 2004)
161957*2^727995 + 1 is prime! (found by FootMaster on 22 Mar 2004)
261917*2^704227+1 is prime! (found by ltd on 08 Mar 2004)
263927*2^639599+1 is prime! (found by FootMaster on 20 Feb 2004)
159503*2^540945+1 is prime! (found by FootMaster on 07 Feb 2004)
172127*2^448743+1 is prime! (found by Citrix on 05 Feb 2004)
247099*2^484190+1 is prime! (found by FootMaster on 05 Feb 2004)
122149*2^578806+1 is prime! (found by FootMaster on 19 Jan 2004)
203761*2^384628+1 is prime! (found by FootMaster on 05 Jan 2004)
224027*2^273967+1 is prime! (found by FootMaster on 12 Dec 2003)
87743*2^212565+1 is prime! (found by Morris Cox on 18 Nov 2003)
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Congrats :) to the PrimeGrid project and all participants
Your numbercrunchings truly
Starless
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what is so hard to understand about 3.1415926535897932384626433832795 ?? 



Congratulations!!!!
BTW: the sieve file for PSP will have to change, won´t it? I will be a little bit faster in the future, no?




It's already been changed. 



congratulations! Is a great result. 



Congrats to everyone who is helping with the Prime Sierpinski Project!!!
____________
John M. Johnson "Novex" 



yes, well, always getting 0 finds does get depressing though ...
Of course, I guess that just about everyone is getting 0 primes found as results ... or maybe I am just lucky ...
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yes, well, always getting 0 finds does get depressing though ...
Of course, I guess that just about everyone is getting 0 primes found as results ... or maybe I am just lucky ...
I finally got my 1st prime so yes I'd agree with you. :)
Actually I generally only sieve now with my 64 bit host but somehow it "accidentally" downloaded a bunch of TPS wus and so far 1 was prime. 



yes, well, always getting 0 finds does get depressing though ...
Of course, I guess that just about everyone is getting 0 primes found as results ... or maybe I am just lucky ...
I finally got my 1st prime so yes I'd agree with you. :)
Actually I generally only sieve now with my 64 bit host but somehow it "accidentally" downloaded a bunch of TPS wus and so far 1 was prime.
Well, I reordered my priorities (AGAIN) and added PrimeGrid back in ... it is a shame they have not made at the least a OSx/Intel version of the applications ...
But, if I am a little less restrictive than I have been in the past... it looks like I can add a few other projects to the mix I run ... though, sadly, some of the ones I would be more inclined to support more seem to be of the mood not to do osx ... even the Intel version.
{Edit}Of course I have only done about 100 or so tasks so I suppose it is a little much to ask ... :)
But, I only have the 2 PCs soon to be only one ...{/edit}
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I'm very curious as I just got another computer and wish to know what the avg. time it takes to do a psp WU. If you have computer speed and stats and then how long it takes that would be awesome, and I would greatly appreciate it.
Thank You
Edit: The power supply is the last item I'm waiting for from newegg and the computer is going to be much different then my other 3, so thats why I asked, otherwise I would just run it on one of mine yet I don't think I'll get an avg result. Hope that helps with the explanation.
____________
John M. Johnson "Novex" 



I'm very curious as I just got another computer and wish to know what the avg. time it takes to do a psp WU. If you have computer speed and stats and then how long it takes that would be awesome, and I would greatly appreciate it.
I'm pretty sure I've seen 310 seconds per psp sieve WU using high end CPUs and overclocked to hell. My unO/C'd Q6700 takes about 340 seconds which is a 10% difference.
I am looking to get a highend cruncher towards the end of the year (when I'll need to heat my apartment again). I will try to break 300 seconds on that one. :)
Then again, the thrill of finding primes is too much for this siever. TSPs take about 180 seconds so I can probably crank out 7580 per hour if I let my quad go nonstop TSP. For a week that is maybe 13k TSP work units.
That can't be right, can it? 



I'm very curious as I just got another computer and wish to know what the avg. time it takes to do a psp WU. If you have computer speed and stats and then how long it takes that would be awesome, and I would greatly appreciate it.
Here's what my computer does for all projects (and you can compare times with your own to figure out the PSP):
TPS : 12 minutes
*PSP : 57 hours*
321 : 20 hours
Cullen : 45 hours
Woodall : 52 hours
Sieve GCW : 45 minutes
Sieve PSP : 22 minutes
4/14/2008 13:08:01Processor: 2 GenuineIntel Genuine Intel(R) CPU T2050 @ 1.60GHz [x86 Family 6 Model 14 Stepping 8]
4/14/2008 13:08:01Processor features: fpu tsc sse sse2 mmx
4/14/2008 13:08:01Memory: 1013.98 MB physical, 2.38 GB virtual
4/14/2008 13:08:01Disk: 111.54 GB total, 92.43 GB free
4/14/2008 13:08:32 1504 floating point MIPS (Whetstone) per CPU
4/14/2008 13:08:32 3098 integer MIPS (Dhrystone) per CPU
Yes, my PSP does take a long time. But I know other computers don't take this much time on their LLR WUs. Fortunately, PSPs have an 11day deadline.
Hope this helps!
____________
. 



FOr me it looks to be about 37 hours on a dual Xeon 3.2 GHz with HT ... if I was running it as just two instead of 4 processors it would be faster, but, history shows that over the long run HT does get you at least 20% improvement over nonHT production ... you have 4 things in flight instead of two and though the each take longer, the THROUGHPUT is better ...
On a dual core AMD 4400 I get about 36 hours for a Cullen ...
The times are approximate of course ...
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Perfect, thanks a ton you guys that helps a lot. And I can relate to the heating of an apartment with so many computers lol, Yes I know its bad but some days it feels over 100 degrees in the office where most are, churning away. But I appreciate your info it does help a ton.
____________
John M. Johnson "Novex" 


JohnHonorary cruncher
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Joined: 21 Feb 06 Posts: 2875 ID: 2449 Credit: 2,681,934 RAC: 0

The Prime Sierpinski Project has discovered another mega prime: 258317*2^5450519+1 (1640776 digits long) and will rank as the 12th largest known prime. It was found by Scott Gilvey (Sloth)...yes, the same person who found PSP's first mega prime...what a wonderful accomplishment. Congratulations!!!
PSP's post can be found here in the Mersenne forum.
While PrimeGrid did not find the prime, it shares credit because of the amount of work it has contributed. This prime would still be years away if not for the combined efforts of PSP and PrimeGrid.
Additionally, PrimeGrid continues to make incredible strides in sieving. The current sieving depth is p=7.2P. When PrimeGrid started last October, sieving was at p=1.5P. A nice goal would be to reach p=10P by the one year anniversary. Based on the progress so far, this looks like a very realistic goal. :)
The speed in which this prime was found would never have been possible without your contributions...both sieving and primality checking (LLR). A special thanks to everyone who participates in PrimeGrid and a big CONGRATULATIONS to the Prime Sierpinski Project.
Good Luck on future finds!
[edit] Yes, a new sieve file will be issued which will be released when the current WU queue empties. Credit will be adjusted accordingly.
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A nice goal would be to reach p=10P by the one year anniversary. Based on the progress so far, this looks like a very realistic goal. :)
I believe a "One Year Anniversary" challenge would help to accomplish this ;)
Peter
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Congratulations to the finder of this incredible big prime!
A nice goal would be to reach p=10P by the one year anniversary. Based on the progress so far, this looks like a very realistic goal. :)
I believe a "One Year Anniversary" challenge would help to accomplish this ;)
Peter
The more often challenges are used to summarize computing power, the less it will succeed, i think. This instrument shouldn't be used too often.
One question: Does this affect the progress of 17oB? 


JohnHonorary cruncher
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Joined: 21 Feb 06 Posts: 2875 ID: 2449 Credit: 2,681,934 RAC: 0

One question: Does this affect the progress of 17oB?
Not really...ok, maybe a little. They still have 6 k's left and now PSP has 12 k's left (3 of which are shared with SoB). SoB is primality testing 6 k's and PSP is primality testing 9 k's.
However, the combined sieve file will be smaller (thus faster) as there are only 15 k's left. So, SoB progress will benefit from this. More info can be found here:
http://www.primegrid.com/forum_thread.php?id=972&nowrap=true#9502
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The current sieving depth is p=7.2P. When PrimeGrid started last October, sieving was at p=1.5P. A nice goal would be to reach p=10P by the one year anniversary. Based on the progress so far, this looks like a very realistic goal. :)
What does "p" and "P" mean ?
____________



JohnHonorary cruncher
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Joined: 21 Feb 06 Posts: 2875 ID: 2449 Credit: 2,681,934 RAC: 0

The current sieving depth is p=7.2P. When PrimeGrid started last October, sieving was at p=1.5P. A nice goal would be to reach p=10P by the one year anniversary. Based on the progress so far, this looks like a very realistic goal. :)
What does "p" and "P" mean ?
A common notation used in sieving is: p  k*b^n+1
Here's an example using a recent factor submission for PSP sieve:
7266111922899983  79817*2^45327351+1
p=7266111922899983
k=79817
b=2
n=45327351
This means that 7266111922899983 is a factor of 79817*2^45327351+1. Therefore, 79817*2^45327351+1 is not prime and does not have to be primality tested (LLR). 79817*2^45327351+1 will be removed from the possible prime candidates.
P is the symbol used for peta (10^15 or 1,000,000,000,000,000). The factors are so large that we refer to them in P or T (tera, 10^12). The factor above would be in the 7.2P to 7.3P range or 7200T to 7300T range. Please see SI prefixes for more information the International System of Units.
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Thank John, I try to explain this in french :
http://www.boincaf.org/content/view/990/289/
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Wow it appears that ~95,000 k/n pairs below n=50M where eliminated as a result of the new prime and propably some factors removed. So now it only will take 3,653 k/n pairs to be factored before crawling below 900,000 candidates remaining :)
Congrats on your effort everyone, as soon as I finish my own project, I'll come back to help only PSP or SoB, but I really like the BOINC cobblestone credit so I may most likely come back to help LLR attack these remaining kvalues :)
KEP! 



The big 9500 test change was due to all the work from PrimeGrid getting incorporated into the database. All of the 4M5M work that has been completed was just added in.
The new prime took out about 78000 from the roughly 903640 remaining unteseted values below 50M.
PrimeGrid has made a HUGE impact on this project. Beyond just the 9500 testes that were completed there is all the sieve work that has cut down on LLR tests that are needed. PG has so far removed 86900 factors  more then what removing a prime from the list has done. Each LLR test takes longer then 24 hours to complete. At the higher range that is currently being sieved that is probably closer to 30 hours per test.
With everyones help hopefully we can all find another prime or two this year.
S.
edit: and of course after I go back and reread the previous post I see he mentioned all the tests removed below 50M and not the work submitted in the 5M range. 



With everyones help hopefully we can all find another prime or two this year.
Well with a 152 days to go, this means that you will have to find 1 prime every 76 days or less. This means, if the given amount of WU completed per day (~425) is sustained, that you'll have to find a prime for every 32,300 WU... well good luck on that feasible goal... at least I think it feasible because 1 man already this year slayed 2 Megaprime k's on his own... so just imagine what all the LLR runners hopefully coming from currently downed RS, can help us achieve :)
Also since the WUs is really big, it really will also be good for the servers to handle many users through without being heavily overloaded ;)
So whos is up for Sloths challenge to slay 2 more primes this year? Anyone or is he on his own on that long run?
KEP! 



I'm still running PSP (except during the 3day challenge) 



Congratulations!!! Very exciting news.
Let us all keep numbercrunching with pleasure :)
Cheers Ana
On 4 April, 2008, 22:22 UTC, the Prime Sierpinski Project discovered their first mega prime: 265711*2^4858008+1 (1462412 digits long). It was found on PSP's LLRNet by Scott Gilvey (Sloth) using an Intel C2D E4500 @ 2.2 GHz with 2 GB RAM. While PrimeGrid did not find the prime, we share credit because of the amount of work we have contributed. This prime would still be at least year or so away if not for our combined efforts now.
Additionally, just last week, we reached a major milestone with PSP sieve. PrimeGrid has now sieved more work than the combined efforts of the Seventeen or Bust (since 2003) and PSP (since 2004) manual sieves...and did it in less than 6 months. This is an incredible accomplishment earlier than expected in large part because of the success of the Ides of March Challenge. The speed in which this was achieved would never have been possible without your contributions.
A hearty thanks to everyone who participates in PrimeGrid and a big CONGRATULATIONS to the Prime Sierpinski Project.
Thank you from the PrimeGrid staff.

To participate in PSP, please visit your PrimeGrid preferences page and select either PSP sieve or PSP LLR. Additionally, you can visit the Prime Sierpinski Project and learn about how to contribute in a minimally more manual way.

As for the Prime Sierpinski Project, here are some more details.
PSP is attempting to solve the Prime Sierpinski Problem.
We look at a special class of prime numbers called proth numbers which have the general formula k*2^n+1. We further specialize our search by looking at numbers for which k is prime in k*2^n+1. Furthermore, it has been proven that there exists an infinite number of prime k's such that k*2^n+1 can never be prime. These k's are called prime sierpinski numbers.
The smallest proven prime sierpinski number is 271129. We are looking at all prime k's below this number and trying to prove that they are not sierpinski numbers and thus studying the distribution of primes of the forum k*2^n+1. The easiest way to prove that a k is not a prime sierpinski number is to find a prime for that k.
There are 13 candidates remaining for which we need to find a prime. PSP is searching for 10 of these while 3 others are part of the Seventeen or Bust project.
Here's a list of the remaining k's:
79309
79817
90527
152267
156511
168451
222113
225931
237019
258317
10223  SoB
22699  SoB
67607  SoB
List of Primes already found!
265711*2^4858008+1 is prime! (found by Sloth on 04 Apr 2008)
222361*2^2854840+1 is prime! (found by Shy24 on 31 Aug 2006)
214519*2^1929114+1 is prime! (found by ltd on 2 Jan 2006)
149183*2^1666957+1 is prime! (found by ltd on 7 Oct 2005)
241489*2^1365062+1 is prime! (found by Citrix on 25 Jan 2005)
216751*2^903792+1 is prime ! (found by ltd on 10 May 2004)
161957*2^727995 + 1 is prime! (found by FootMaster on 22 Mar 2004)
261917*2^704227+1 is prime! (found by ltd on 08 Mar 2004)
263927*2^639599+1 is prime! (found by FootMaster on 20 Feb 2004)
159503*2^540945+1 is prime! (found by FootMaster on 07 Feb 2004)
172127*2^448743+1 is prime! (found by Citrix on 05 Feb 2004)
247099*2^484190+1 is prime! (found by FootMaster on 05 Feb 2004)
122149*2^578806+1 is prime! (found by FootMaster on 19 Jan 2004)
203761*2^384628+1 is prime! (found by FootMaster on 05 Jan 2004)
224027*2^273967+1 is prime! (found by FootMaster on 12 Dec 2003)
87743*2^212565+1 is prime! (found by Morris Cox on 18 Nov 2003)
____________
Hallo! I'm living in Australia now. I'm a scientist & neruopsychologist who loves music, caring for orphaned/injured Australian wildlife (Kangaroos, Raptors, & Sssssnakes). I am truly passionate in the field of...consuming chocolates. Anastasia L :) 



fantastic, lets find the rest :)

Will



JohnHonorary cruncher
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Joined: 21 Feb 06 Posts: 2875 ID: 2449 Credit: 2,681,934 RAC: 0

On 19 June, 2010, 20:51 UTC, the Prime Sierpinski Project discovered another Mega Prime:
90527*2^9162167+1
The prime is 2,758,093 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 12th overall. This is PSP's third Mega Prime, the first found by using PRPNet, and the largest found Mega Prime using LLR. The project has now found 18 primes total. There are now 11 primes left to solve the Prime Sierpinski Problem.
It was found on PSP's PRPNet by Patrice Salah (Bold_Seeker) of the Netherlands using an Intel Q6600 @ 2.83 GHz with 2 GB RAM. Patrice is a member of the Dutch Power Cows team.
The prime was verified by Lars Dausch using an Intel i7 920 @ 2.66GHz with 12 GB RAM. This computer took about 2.5 days to complete the primality test.
Credits for the discovery are as follows:
 Patrice Salah (Netherlands), discoverer
 The Prime Sierpinski Problem
 PrimeGrid, et al.
 Srsieve, sieving program developed by Geoff Reynolds
 LLR, primality program developed by Jean Penné
This is another success for the collaboration of PrimeGrid and the Prime Sierpinski Project. A big thanks to everyone who participates in PrimeGrid and a big CONGRATULATIONS to the Prime Sierpinski Project.
Thank you from the PrimeGrid staff.

To participate in PSP, please visit your PrimeGrid preferences page and select either PSP (Sieve) or PSP (LLR). Additionally, you can visit the Prime Sierpinski Project and learn about how to contribute manually or through their PRPNet.

As for the Prime Sierpinski Project, here are some more details.
PSP is attempting to solve the Prime Sierpinski Problem.
We look at a special class of prime numbers called proth numbers which have the general formula k*2^n+1. We further specialize our search by looking at numbers for which k is prime in k*2^n+1. Furthermore, it has been proven that there exists an infinite number of prime k's such that k*2^n+1 can never be prime. These k's are called prime Sierpinski numbers.
The smallest proven prime Sierpinski number is 271129. We are looking at all prime k's below this number and trying to prove that they are not Sierpinski numbers and thus studying the distribution of primes of the forum k*2^n+1. The easiest way to prove that a k is not a prime Sierpinski number is to find a prime for that k.
There are 11 candidates remaining for which we need to find a prime. PSP is searching for 8 of these while 3 others are part of the Seventeen or Bust project.
Here's a list of the remaining k's:
79309
79817
152267
156511
168451
222113
225931
237019
10223  SoB
22699  SoB
67607  SoB
List of Primes already found!
90527*2^9162167+1 is prime! (found by Bold_Seeker on 19 Jun 2010)
258317*2^5450519+1 is prime! (found by Sloth on 28 Jul 2008)
265711*2^4858008+1 is prime! (found by Sloth on 04 Apr 2008)
222361*2^2854840+1 is prime! (found by Shy24 on 31 Aug 2006)
214519*2^1929114+1 is prime! (found by ltd on 2 Jan 2006)
149183*2^1666957+1 is prime! (found by ltd on 7 Oct 2005)
241489*2^1365062+1 is prime! (found by Citrix on 25 Jan 2005)
216751*2^903792+1 is prime ! (found by ltd on 10 May 2004)
161957*2^727995 + 1 is prime! (found by FootMaster on 22 Mar 2004)
261917*2^704227+1 is prime! (found by ltd on 08 Mar 2004)
263927*2^639599+1 is prime! (found by FootMaster on 20 Feb 2004)
159503*2^540945+1 is prime! (found by FootMaster on 07 Feb 2004)
172127*2^448743+1 is prime! (found by Citrix on 05 Feb 2004)
247099*2^484190+1 is prime! (found by FootMaster on 05 Feb 2004)
122149*2^578806+1 is prime! (found by FootMaster on 19 Jan 2004)
203761*2^384628+1 is prime! (found by FootMaster on 05 Jan 2004)
224027*2^273967+1 is prime! (found by FootMaster on 12 Dec 2003)
87743*2^212565+1 is prime! (found by Morris Cox on 18 Nov 2003)
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