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 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.
On 11 October 2018, 22:54:34 UTC, PrimeGrid's 27121 Prime Search, through PRPNet and in collaboration with the 12121 Search (k=27 sister project), has found the mega prime:
27·27046834+1
The prime is 2,121,310 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 48 th overall.
The discovery was made by Andrew M. Farrow ( Nortech) of Australia
using an Intel(R) Xeon(R) CPU E3-1245 v6 @ 3.70GHz Processor with 16GB RAM, running Linux.
This computer took about 1 hour and 13 minutes to complete the primality test using multithreaded LLR.
For more information, please see the Official Announcement.
On 26 September 2018, 13:24:01 UTC, PrimeGrid's Generalized Fermat Prime Search found the Generalized Fermat mega prime:
5828034262144+1
The prime is 1,773,542 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 9 th for Generalized Fermat primes and 66 th overall.
The discovery was made by Rob Gahan ( Robish) of Ireland
using an NVIDIA GeForce GTX Titan X in an Intel(R) Core(TM) i7-5930K CPU at 3.50GHz with 32GB RAM, running Windows 10 Core Edition.
This GPU took about 2 hours and 36 minutes to probable prime (PRP) test with GeneferOCL3.
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.
This computer took about 5 hours and 57 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 
Substantial Planned Downtime Friday
This Friday, PrimeGrid is moving to new servers. Everything (except our Discord chat server) will be offline for several hours. Since the forums will be down, Discord will be the only way to communicate with us.
More information can be found on the forums here:
http://www.primegrid.com/forum_thread.php?id=7592&nowrap=true#122692
19 Nov 2018 | 21:27:55 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
New PrimeGrid Policy - Monetization of BOINC credit
PrimeGrid has decided not to participate in any system that monetizes our BOINC credit. For more details please see http://www.primegrid.com/forum_thread.php?id=8272.
4 Nov 2018 | 12:36:27 UTC
· Comment
27 Mega Prime!
On 11 October 2018, 22:54:34, PrimeGrid’s 27121 Prime Search, through PRPNet and in collaboration with the 12121 Search (k=27 sister project), has found the mega prime:
27*2^7046834+1
The prime is 2,121,310 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 48th overall.
The discovery was made by Andrew M. Farrow (Nortech) of Australia using an Intel(R) Xeon(R) CPU E3-1245 v6 @ 3.70GHz Processor with 16GB RAM, running Linux. This computer took about 1 hour 13 minutes to complete the primality test using LLR.
For more details, please see the official announcement.
22 Oct 2018 | 10:23:16 UTC
· Comment
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Newly reported primes(Mega-primes are in bold.)
106854672^32768+1 (Johny); 2585*2^1506031+1 (CGB); 4185555827175*2^1290000-1 (Margus); 44427620^65536+1 (vaughan); 44401238^65536+1 (urbanknight); 106752044^32768+1 (vaughan); 106742024^32768+1 (Soulfly); 44408348^65536+1 (Tejas); 54548788^131072+1 (Olgar); 4183020633165*2^1290000-1 (Mason); 8523*2^1505866+1 (Olgar); 4180477953375*2^1290000-1 (FishFry); 106542368^32768+1 (马致远); 106500736^32768+1 (Soulfly); 106474810^32768+1 (Rick Reynolds); 4180631139027*2^1290000-1 (FishFry); 106424198^32768+1 (vaughan); 106431156^32768+1 (Fudge); 4181114008617*2^1290000-1 (dthonon); 4473*2^1505630+1 (qbrent) 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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