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 14 December 2018, 07:07:34 UTC, PrimeGrid's Generalized Fermat Prime Search found the Generalized Fermat mega prime:
6291332262144+1
The prime is 1,782,250 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 10 th for Generalized Fermat primes and 66 th overall.
The discovery was made by Karsten Freihube ( KFR) of Germany
using an NVIDIA GeForce GTX 1060 in an Intel(R) Core(TM) i7-4790 CPU at 3.60GHz with 16GB RAM, running Windows 10 Proffesional Edition.
This GPU took about 35 minutes to probable prime (PRP) test with GeneferOCL2.
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 and 59 minutes to complete the primality test using multithreaded LLR.
For more information, please see the Official Announcement.
On 12 December 2018, 05:32:25 UTC, PrimeGrid's Generalized Fermat Prime Search found the Generalized Fermat mega prime:
628774262144+1
The prime is 1,782,186 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 10 th for Generalized Fermat primes and 66 th overall.
The discovery was made by Greg Miller ( Olgar) of the United States
using an NVIDIA GeForce GTX 1050 in an AMD Phenom(TM) II x4 965 CPU with 16GB RAM, running Windows 10 Professional Edition.
This GPU took about 60 minutes to probable prime (PRP) test with GeneferOCL2.
Greg is a member of the USA team.
The PRP was confirmed prime by an Intel(R) Xeon(R) CPU E3-1240 v6 @ 3.70GHz running Linux.
This computer took about 15 hours and 44 minutes to complete the primality test using LLR.
For more information, please see the Official Announcement.
On 31 October 2018, 00:42:47 UTC, PrimeGrid's Generalized Fermat Prime Search found the Generalized Fermat mega prime:
10590941048576+1
The prime is 6,317,602 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 1 st for Generalized Fermat primes and 13 th overall.
This is the second-largest prime found by PrimeGrid, and the second-largest non-Mersenne prime.
The discovery was made by Rob Gahan ( Robish) of Ireland
using an Nvidia GeForce GTX 1080 in an Intel(R) Core(TM) i7-7820HK CPU at 2.90GHz with 32GB RAM, running Microsoft Windows 10 Professional Edition.
This GPU took about 3 hours and 35 minutes to probable prime (PRP) test with GeneferOCL4.
Rob is a member of the Storm 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 Edition.
This computer took about 4 days, 5 hours and 54 minutes to complete the primality test using multithreaded LLR.
For more information, please see the Official Announcement.
Other significant primes
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News 
Conjunction of Venus & Jupiter Challenge starts in 8 hours!
In about 8 hours, at 5:43:00 UTC January 7th, we kick off our 2019 challenge series with a 15 day SoB (Seventeen or Bust) challenge.
As with last year, the goal of this challenge is to accelerate the SoB double check. With a good challenge this year, we may be able to complete the double check in 2019!
More information and discussion about the challenge can be found in this forum thread.
6 Jan 2019 | 21:54:38 UTC
· Comment
Another GFN-262144 Mega Prime!
On 14 December 2018, 07:07:34 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:
6291332^262144+1
The prime is 1,782,250 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 10th for Generalized Fermat primes and 66th overall.
The discovery was made by Karsten Freihube (KFR) of Germany using an NVIDIA GeForce GTX 1060 in an Intel(R) Core(TM) i7-4790 CPU at 3.60GHz with 16GB RAM, running Windows 10 Proffesional Edition. This GPU took about 35 minutes to probable prime (PRP) test with GeneferOCL2.
The prime was verified on 14 December 2018, 14:47:41 by Andreas Zenker (Buddy) of Austria Republic using an NVIDIA GeForce GTX 1060 GPU in an Intel(R) Core(TM)2 Quad CPU at 2.50GHz 4GB RAM, running Windows 7 Professional Edition. This GPU took about 42 minutes to probable prime (PRP) test with GeneferOCL2. Andreas is a member of Team PC-Reflate.
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 59 minutes to complete the primality test using LLR.
For more details, please see the official announcement.
22 Dec 2018 | 13:28:43 UTC
· Comment
GFN-262144 Mega Prime!
On 12 December, 05:32:25 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:
6287774^262144+1
The prime is 1,782,186 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 10th for Generalized Fermat primes and 66th overall.
The discovery was made by Greg Miller (Olgar) of the United States using an NVIDIA GeForce GTX 1050 in an AMD Phenom(TM) II x4 965 CPU with 16GB RAM, running Windows 10 Professional Edition. This GPU took about 60 minutes to probable prime (PRP) test with GeneferOCL2. Greg is a member of the USA 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 15 hours 44 minutes to complete the primality test using LLR.
For more details, please see the official announcement.
22 Dec 2018 | 13:09:42 UTC
· Comment
Fix for Slow Forums
If you've been experiencing slow-loading forums at PrimeGrid, or, for that matter, any BOINC project's forums, the reason is because the Free-DC website has been down a lot recently.
Many people use forum signature images from Free-DC, which your browser loads when it displays forum messages. If Free-DC is down, your browser has to wait for the image request to Free-DC to time out. That's why the forum pages load slowly.
If you want forum pages to load more quickly, go to the Community Preferences page and check the "hide signatures" box. Don't forget to click on the "Update" button at the bottom.
10 Nov 2018 | 1:02:09 UTC
· Comment
GFN-1048576 Mega Prime!
On 31 October 2018, 00:42:47 UTC, PrimeGrid’s Generalized Fermat Prime Search found the Generalized Fermat mega prime:
1059094^1048576+1
The prime is 6,317,602 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 1st for Generalized Fermat primes and 13th overall. This is the second-largest prime found by PrimeGrid, and the second-largest non-Mersenne prime.
The discovery was made by Rob Gahan (Robish) of Ireland using a Nvidia GeForce GTX 1080 in an Intel(R) Core(TM) i7-7820HK CPU at 2.90GHz with 32GB RAM, running Microsoft Windows 10 Professional Edition. This GPU took about 3 hours 35 minutes to probable prime (PRP) test with GeneferOCL4. Rob is a member of the Storm 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 Edition. This computer took about 4 days, 5 hours, 54 minutes to complete the primality test using multithreaded LLR.
For more details, please see the official announcement.
5 Nov 2018 | 16:42:53 UTC
· Comment
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Newly reported primes(Mega-primes are in bold.)
112858572^32768+1 (Johny); 112862222^32768+1 (Renix1943); 112681410^32768+1 (Renix1943); 55645700^131072+1 (bcavnaugh); 3269*2^1510937+1 (CGB); 112492494^32768+1 (Johny); 112478472^32768+1 (Soulfly); 112475504^32768+1 (Soulfly); 112448974^32768+1 (Johny); 55579418^131072+1 (bcavnaugh); 4259651228877*2^1290000-1 (Charles Jackson); 1573*2^1510780+1 (Scott Cox); 4257009096375*2^1290000-1 (Adam.Nuclear); 112239238^32768+1 (Henriksson); 112205972^32768+1 (Henriksson); 7255*2^1510824+1 (Randall J. Scalise); 112189290^32768+1 (Ed Snell); 4259520125115*2^1290000-1 ([AF>Libristes] ElGuillermo); 2555*2^1510763+1 (Robert); 3089*2^1510697+1 (CGB) Last 24 hoursTop participants by work done in the last 24 hours | Top teams by work done in the last 24 hours |
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