PrimeGrid’s
Generalized Fermat Prime Search
On 31 October 2018, 00:42:47 UTC, PrimeGrid’s Generalized Fermat Prime Search found theGeneralized Fermat mega prime:
10590941048576+1
The prime is 6,317,602 digits long and enters Chris Caldwell's “The Largest Known Primes
Database” (http://primes.utm.edu/primes) ranked 1st for Generalized Fermat primes and 13thoverall. This is the second-largest prime found by PrimeGrid, and the second-largest nonMersenne prime.
The discovery was made by Rob Gahan of Ireland using a Nvidia GeForce GTX 1080 in anIntel(R) Core(TM) i7-7820HK CPU at 2.90GHz with 32GB RAM, running Microsoft Windows 10Professional Edition. This GPU took about 3 hours 35 minutes to probableprime (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, 5hours, 54 minutes to complete the primality test using multithreaded LLR.
The credits for the discovery are as follows:
1.
2.
3.
4.
5.
6.

Rob Gahan (Ireland), discoverer
PrimeGrid, et al.
AthGFNSieve, sieve program developed by David Underbakke
GFNSvCUDA , sieve program developed by Anand Nair
GeneferOCL, probable prime program developed by Yves Gallot
LLR, primality program developed by Jean Penné

Entry in “The Largest Known Primes Database” can be found here:
https://primes.utm.edu/primes/page.php?id=125753
Using a single PC would have taken years to find this prime. So this timely discovery would nothave been possible without the hundreds of volunteers who contributed their spare CPU cycles. Aspecial thanks to everyone who offered their advice and/or computing power to the search especially Yves Gallot, Iain Bethune, David Underbakke, Anand Nair, Mark Rodenkirch and GeoffReynolds who were major forces in moving the project forward. Also, thank you to all the sievers,
especially Honza Cholt and Jim Breslin. A final thanks to Michael Goetz for porting to BOINC.
The Generalized Fermat Prime Search will continue to seek even larger primes. To join thesearch please visit PrimeGrid: http://www.primegrid.com

PrimeGrid’s
Generalized Fermat Prime Search
About PrimeGrid
PrimeGrid is a distributed computing project, developed by Rytis Slatkevičius and currentlymanaged by Iain Bethune, James Breslin, Scott Brown, Ulrich Fries, Michael Goetz, RogerKarpin, Rytis Slatkevičius, and Van Zimmerman.
PrimeGrid utilizes BOINC and PRPNet to search for primes with the primary goal of bringing theexcitement of prime finding to the "everyday" computer user. Simply download the software andlet your computer do the rest. 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.
BOINCThe Berkeley Open Infrastructure for Network Computing (BOINC) is a software platform
for distributed computing using volunteered computer resources. It allows users toparticipate in multiple distributed computing projects through a single program. Currently
BOINC is being developed by a team based at the University of California, Berkeley led byDavid Anderson.
This platform currently supports projects from biology to math to astronomy. For more
information, please visit BOINC: http://boinc.berkeley.edu
PRPNet
PRPNet is a client/server application written by Mark Rodenkirch that is specificallydesigned to help find prime numbers of various forms. It is easily ported between various
OS/hardware combinations. PRPNet does not run each PRP test itself, but relies on helper
programs, such as LLR, PFGW, phrot, wwww, and genefer to do the work.
For more information, please visit PrimeGrid’s PRPNet forum thread:
http://www.primegrid.com/forum_thread.php?id=1215
For more information about PrimeGrid and a complete list of available prime search projects,
please visit: http://www.primegrid.com