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:
6287774262144+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 
PrimeGrid and BOINC are looking for experienced Macintosh Developers
PrimeGrid is currently looking for a volunteer developer to build, test and maintain Mac apps. The current developer of PrimeGrid (and other applications that are used in the mathematics/prime search world) is no longer able to help us maintain the applications, which means that we may need to drop support for Macs over time (no such changes are planned right now or in the immediate future).
If you are able to help us, please don't hesitate to get in touch.
Moreover, the Berkeley Open Infrastructure for Network Computing (BOINC) open source project, which is the software infrastructure used by PrimeGrid and many other volunteer distributed computing projects, is also looking for volunteers to develop and maintain the BOINC client on Macintosh. The BOINC Client and Manager are C++ cross-platform code supporting MS Windows, Mac, Linux, and several other operating systems. BOINC currently has a number of volunteer developers supporting Windows and Linux, but their main Mac developer is winding down his involvement after many years. He is prepared to help a few new Mac developers get up to speed.
If you have Mac development experience and are interested in volunteering time to help support and maintain the BOINC Mac client please have a look at the more detailed description here: https://boinc.berkeley.edu/trac/wiki/MacDeveloper
If you are not a Mac developer, but have other skills and are interested in contributing to BOINC, the link above also has more general information.
19 Feb 2019 | 11:35:16 UTC
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Tips for faster forums
If you find that loading forum messages is slow, there are two settings you can change on the Community Preferences page:
* Check the "Hide Badges" box. If you're not in Europe you probably have a ping time above 100 ms, and loading all those little badge images that everyone earns takes a while. Have you seen how many different badges people have? A tenth of a second for each one adds up.
* Check the "Show images as links" box. If a forum post contains an image from a third party site, including all badge or credit signature images, and that site is down or slow, it will significantly slow down loading the forum message page.
You can leave avatars and signatures turned on if you wish. They don't affect forum speed significantly.
7 Feb 2019 | 20:33:27 UTC
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Feeling Lucky? World Record Prime Search Active Again
PrimeGrid now has a new project called "Do You Feel Lucky?" This is a world record prime search using GFN-22 with b starting at 846,398, which is the first b not removed by sieving where b^4194304+1 is greater than the current world record. Due to software limitations combined with the size of the numbers involved, this is a GPU-only project. The project will continue separate from the existing GFN22 search, and should the current world record increase, this project will be adjusted to then search beyond that new record.
For the full project details, please see this forum post.
So now "you've got to ask yourself one question: 'Do I feel lucky?' Well, do ya...?"
4 Feb 2019 | 17:00:20 UTC
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2019 Tour de Primes Starts February 1st!
       
Our annual Tour de Primes challenge begins in a little over one day from now, and runs for the entire month of February.
Unlike other challenges, you don't get a trophy just for participating -- you have to actually find primes to win something!
As with last year, we will be awarding special "jersey badges" to the winners in four different categories. We're also continuing the tradition of offering special badges that are available to anyone who finds an eligible prime!
Come join us in February. More information about Tour de Primes can be found here.
30 Jan 2019 | 20:18:34 UTC
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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
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Newly reported primes(Mega-primes are in bold.)
3005*2^1528923+1 (Scott Brown); 8537*2^1529043+1 (Olgar); 5825*2^1528821+1 (Scott Brown); 55836122^65536+1 (Howdy2u2); 55837944^65536+1 (Brook Harste); 4845*2^1528682+1 (Scott Brown); 8263*2^1528602+1 (4bc3); 8555*2^1528599+1 (dthonon); 55740434^65536+1 (CGB); 7835*2^1528449+1 (SEARCHER); 4300991055405*2^1290000-1 ([AF>Libristes] ElGuillermo); 5935*2^1528100+1 (FishFry); 657*2^2705620+1 (Keith); 3131*2^1528073+1 (Darryl); 9809*2^1527889+1 (ILW8); 2229*2^1524714+1 (Randall J. Scalise); 57704312^131072+1 (DeleteNull); 57694224^131072+1 (dh1saj); 6609*2^1527883+1 (Grebuloner); 55396316^65536+1 (Mektacular) 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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