Download Prime95 29.1

The distributed computing project Gimps, which stands for Great Internet Mersenne Prime Search, searches for Mersenne primes. These are primes that are exactly one less than a power of two, or 2n – 1. The first four n-numbers to form the first four Mersenne primes are 2, 3, 5 and 7, where respectively 3, 7, 31 and 127 comes out. The required program is called Prime95 and is listed under a own license released. Version 29.1 is recent appeared for FreeBSD, Linux (32, 64bit), macOS and Windows (32, 64bit), of course you can also source the source code. The list of improvements looks like this:

New features in Version 29.1 or prime95.exe

• Faster trial factoring for machines that support FMA (Haswell and later). Multi-threaded trial factoring now supports more than one thread sieving for small primes. Several tuning parameters added – see undoc.txt.
• The portable library, hwloc, for analyzing a machine’s topology is now used. This replaces the buggy code prime95 used to detect hyperthreading. It also eliminates the need for AffinityScramble2. Running a benchmark will output this topology information to results.txt.
• AVX-512 trial factoring support added.
• Dialog box for benchmarking added.
• In the Test/Worker Windows dialog box you no longer choose how many threads each worker uses. Instead, you choose how many CPU cores each worker uses. There affinity options have been removed. There are two new options that will decide if each worker also uses hyperthreading.