About
PrimeGrid's primary goal is to advance mathematics by enabling everyday computer users to contribute their system's processing power towards prime finding. By simply
downloading and installing BOINC and attaching to the PrimeGrid project,
participants can choose from a variety of prime forms to search. With a little patience, you may find a large or even record
breaking prime and enter into Chris Caldwell's The Largest Known Primes Database as
a Titan!
PrimeGrid's secondary goal is to provide relevant educational materials about primes. Additionally, we wish to contribute to the
field of mathematics.
Lastly, primes play a central role in the cryptographic systems which are used for computer security. Through the study of prime
numbers it can be shown how much processing is required to crack an encryption code and thus to determine whether current
security schemes are sufficiently secure. PrimeGrid is currently running several sub-projects:
- 321 Prime Search: searching for
mega primes of the form 3·2n±1.
- Cullen-Woodall Search: searching for
mega primes of forms n·2n+1 and
n·2n−1.
- Extended Sierpinski Problem: helping solve the Extended Sierpinski Problem.
- Generalized Fermat Prime Search: searching for
megaprimes of the form b2n+1.
- Prime Sierpinski Project: helping Prime Sierpinski Project solve the Prime Sierpinski Problem.
- Proth Prime Search: searching for primes of the form k·2n+1.
- Seventeen or Bust: helping to solve the Sierpinski Problem.
- Sierpinski/Riesel Base 5: helping to solve the Sierpinski/Riesel Base 5 Problem.
- Sophie Germain Prime Search: searching for primes p and 2p+1.
- The Riesel problem: helping to solve the Riesel Problem.
Recent Significant Primes
On 29 June 2019, 00:54:18 UTC, PrimeGrid's Generalized Fermat Prime Search found the Generalized Fermat mega prime:
2877652524288+1
The prime is 3,386,397 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 3 rd for Generalized Fermat primes and 26 th overall.
The discovery was made by Roman Vogt ( Tabaluga) of Germany
using an NVIDIA GeForce GTX 1060 in an Intel(R) Core(TM) i7-2700K CPU @ 3.50GHz CPU with 16GB RAM, running Windows 10.
This computer took about 1 hour and 42 minutes to probable prime (PRP) test with GeneferOCL5.
Roman is a member of the Sicituradastra. team.
The PRP was confirmed prime by an Intel(R) Xeon(R) CPU E3-1240 v6 @ 3.70GHz with 4GB RAM, running Linux. This computer took about 25 hours 53 minutes to complete the primality test using multithreaded LLR.
For more information, please see the Official Announcement.
On 23 June 2019, 14:39:48 UTC, PrimeGrid's Sierpiński/Riesel Base 5 Problem project eliminated k=322498 by finding the mega prime:
322498·52800819-1
The prime is 1,957,694 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 63 rd overall and is the largest known base 5 prime. 67 k's now remain in the Riesel Base 5 problem.
The discovery was made by Jordan Romaidis of the United States
using an Intel(R) Xeon(R) Gold 5120 CPU @ 2.20GHz with 96GB RAM running Microsoft Windows 10 Enterprise x64 Edition.
This computer took about 25 hours and 28 minutes to primality test using multithreaded LLR.
Jordan is a member of the San Francisco team.
For more information, please see the Official Announcement.
On 21 June 2019, 01:30:42 UTC, PrimeGrid's Sierpiński/Riesel Base 5 Problem project eliminated k=88444 by finding the mega prime:
88444·52799269-1
The prime is 1,956,611 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 63 rd overall and is the largest known base 5 prime. 68 k's now remain in the Riesel Base 5 problem.
The discovery was made by Scott Brown of the United States
using an Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz with 32GB RAM running Microsoft Windows 10 Professional x64 Edition.
This computer took about 5 hours and 29 minutes to primality test using multithreaded LLR.
Scott is a member of the Aggie The Pew team.
For more information, please see the Official Announcement.
Other significant primes
|
News 
Upcoming REQUIRED changes to app_config.xml
If you don't know what app_config.xml is, or if you don't use it for PrimeGrid's LLR apps, you can ignore this notice. This doesn't affect you.
But if you are using app_config.xml on any of our LLR apps, we are changing the plan class of the LLR app versions, and therefore your app_config.xml won't work after the changes. For details, as well as what you should do right now, please see this message. Comments, questions, and discussion are also located in that thread.
22 Aug 2019 | 15:55:33 UTC
· Comment
Be careful with BOINC computers on the Internet
A lot of us use Cloud servers such as AWS, or make our home computers or our computers at work accessible on the Internet so we can control their BOINC clients remotely.
I was looking through the logs of some Azure servers I have running BOINC, and saw this on one of them:
10316 8/7/2019 11:39:23 AM GUI RPC request from non-allowed address 2.0.25.129
10648 8/7/2019 1:09:27 PM GUI RPC request from non-allowed address 2.0.42.193
10649 8/7/2019 1:09:27 PM 256 connections rejected in last 10 minutes
In fact, a similar address (somewhere in France, supposedly) tried to connect to the BOINC client on four of my BOINC machines. This has been happening since at least July.
If the BOINC client on your computers is accessible from the Internet, I advise putting your specific IP address (or addresses) into remote_hosts.cfg rather than leaving it open to the world, or doing the same in a firewall (or both). And use a strong password.
If you don't think this is important... anyone who successfully connects to the BOINC client on your computer can attach it to their own BOINC server, which can then send it tasks that can easily install malicious payloads such as key loggers, spam relays, DDOS bots, and other bad stuff.
EDIT: If this is all Greek to you and you don't know what I'm talking about, you're probably not at risk. BOINC starts off with remote access disabled. You have to explicitly go and change configuration files to enable remote access, and probably modify your firewall as well. If you haven't done that, you're okay.
7 Aug 2019 | 20:41:03 UTC
· Comment
GFN-524288 Mega Prime!
On 29 June 2019, 00:54:18 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:
2877652^524288+1
The prime is 3,386,397 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 3rd for Generalized Fermat primes and 26th overall.
The discovery was made by Roman Vogt (Tabaluga) of Germany using an NVIDIA GeForce GTX 1060 in an Intel(R) Core(TM) i7-2700K CPU @ 3.50GHz CPU with 16GB RAM, running Windows 10. This GPU took about 1 hour and 42 minutes to probable prime (PRP) test with GeneferOCL5. Roman is a member of the Sicituradastra. team.
The PRP was verified on 29 June 2019, 08:52:47 by Carlo Villa (carlo) using an NVIDIA GeForce 830M in an Intel(R) Core(TM) i5-5200U CPU @ 2.20GHz with 8GB RAM, running Windows 10. This GPU took about 16 hours and 55 minutes to probable prime (PRP) test with GeneferOCL5.
The PRP was confirmed prime by an Intel(R) Xeon(R) CPU E3-1240 v6 @ 3.70GHz with 4GB RAM, running Linux. This computer took about 25 hours 53 minutes to complete the primality test using multithreaded LLR.
For more details, please see the official announcement.
8 Jul 2019 | 12:20:47 UTC
· Comment
Another New SR5 Mega Prime!
On 23 June 2019, 14:39:48 UTC, PrimeGrid’s Sierpiński/Riesel Base 5 Problem project eliminated k=322498 by finding the mega prime:
322498*5^2800819-1
The prime is 1,957,694 digits long and enters Chris Caldwell's “The Largest Known Primes Database” ranked 63rd overall and is the largest known base 5 prime. 67 k’s now remain in the Riesel Base 5 problem.
The discovery was made by Jordan Romaidis of the United States using an Intel(R) Xeon(R) Gold 5120 CPU @ 2.20GHz with 96GB RAM running Microsoft Windows 10 Enterprise x64 Edition. This computer took 25 hours and 28 minutes to complete the primality test using multithreaded LLR. Jordan is a member of the San Francisco team.
The prime was verified on 24 June 2019, 20:59:33 UTC by Scott Brown of the United States using an AMD FX(tm)-8350 Eight-Core Processor with 16GB RAM running Microsoft Windows 10 Core x64 Edition. This computer took about 53 hours and 51 minutes to complete the primality test using multithreaded LLR. Scott is a member of the Aggie The Pew team.
For more details, please see the official announcement.
28 Jun 2019 | 20:11:13 UTC
· Comment
New SR5 Mega Prime!
On 21 June 2019, 01:30:42 UTC, PrimeGrid’s Sierpiński/Riesel Base 5 Problem project eliminated k=88444 by finding the mega prime:
88444*5^2799269-1
The prime is 1,956,611 digits long and enters Chris Caldwell's “The Largest Known Primes Database” ranked 63rd overall and is the largest known base 5 prime. 68 k’s now remain in the Riesel Base 5 problem.
The discovery was made by Scott Brown of the United States using an Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz with 32GB RAM running Microsoft Windows 10 Professional x64 Edition. This computer took 5 hours and 29 minutes to complete the primality test using multithreaded LLR. Scott is a member of the Aggie The Pew team.
The prime was verified on 21 June 2019, 14:50:01 UTC by Dave Sunderland (DaveSun) using an Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz with 16GB RAM running Microsoft Windows 10 Core x64 Edition. This computer took about 12 hours and 32 minutes to complete the primality test using multithreaded LLR.
For more details, please see the official announcement.
28 Jun 2019 | 19:55:53 UTC
· Comment
... more
News is available as an RSS feed 
Newly reported primes(Mega-primes are in bold.)
137802120^32768+1 (Darryl); 4603027289637*2^1290000-1 (Kouhki); 1571*2^3323493+1 (Randall J. Scalise); 62146946^131072+1 (Robish); 137557074^32768+1 (Kellen); 137507442^32768+1 (Darryl); 2319*2^3323402+1 (bparsonnet); 137366688^32768+1 (Kellen); 1431*2^1544367+1 (Randall J. Scalise); 65444914^65536+1 (Nick); 65432626^65536+1 (serge); 137257978^32768+1 (boss); 3351*2^1544361+1 (Darryl); 4599443324247*2^1290000-1 (Dave); 137211778^32768+1 (o-ando); 2765*2^1544271+1 (Randall J. Scalise); 137148446^32768+1 (Brian R Kaczala); 137119120^32768+1 (Darryl); 65357568^65536+1 (Nick); 4596379921527*2^1290000-1 (Lobsterstew) Last 24 hoursTop participants by work done in the last 24 hours | Top teams by work done in the last 24 hours |
| 
