Prime95

ADDED ON 2024-08-06

PLATFORM windows 64-bit

HOMEPAGE [web]

What is Prime95?
Prime95 is an utility used to find Mersenne Prime numbers. Mersenne numbers can be proved composite (not prime) by either finding a factor or by running a PRP (PRobable Prime) or Lucas-Lehmer primality test.

Prime95 is also an handy CPU benchmark and stress test.

Changes in latest version: 30.19 build 20
- Huge improvements to stage 2 of ECM when lots of memory is available.
- Warning: prime.txt and local.txt files are automatically combined into one file. Consider backing up these files before installing.
- Warning: upgrading in the middle of P-1 or ECM stage 2 may restart stage 2 from scratch

New features in Version 30.19 of prime95.exe
1) Edwards ECM curves. Given a reasonable amount of memory, Edwards ECM curves are roughly 10% faster than Montgomery ECM curves used in all earlier prime95 versions.
2) Added support for running ECM stage 2 given a resume file from GMP-ECM. Especially useful when GMP-ECM uses a GPU to run ECM stage 1. Syntax for worktodo entries are:
ECMSTAGE2=k,b,n,c,filename[,B2-or-zero][,skip_curves][,num_curves][,known-factors]
ECMSTAGE2N=filename[,B2-or-zero][,skip_curves][,num_curves][,known-factors]
3) New timestamp options in undoc.txt.
4) Manual communication menu choice will also start proof uploads.
5) From the Test/Primenet... dialog box, turning on Use Primenet will bring up the Test/Worker Windows... dialog box to allow changing work preferences prior to contacting the PrimeNet server.
6) The P-1 and ECM stage 2 vs. stage 1 runtime estimate used for optimal B2 calculations is now compared to the actual so that future estimates will hopefully more accurate.
7) Advanced/Test now creates a PRP worktodo.txt entry for large exponents.