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 Home » Freeware Downloads » Toys, Fun Geek Stuff and Other Software » Prime95 29.1 64bit   
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Prime95 29.1 64bit
Prime95 is a small and easy to use application that allows you to find Mersenne Prime numbers.

Mersenne numbers can be proved composite (not prime) by either finding a factor or by running a Lucas-Lehmer primality test.

Prime numbers have long fascinated amateur and professional mathematicians. An integer greater than one is called a prime number if its only divisors are one and itself. The first prime numbers are 2, 3, 5, 7, 11, etc. For example, the number 10 is not prime because it is divisible by 2 and 5.

A Mersenne prime is a prime of the form 2P-1. The first Mersenne primes are 3, 7, 31, 127, etc. There are only 40 known Mersenne primes.

There are two ways to use this program. The automatic way uses a central server, which we call the PrimeNet server, to get work to do and report your results. Anyone with Internet access, including AOL, CompuServe, and dial-up ISP users should use this method. You do not need a permanent connection to the Internet.

The second method is the manual method. It requires a little more work and monitoring. Recommended for computers with no Internet access or with some kind of firewall problem that prevents the automatic method from working.

New features in Version 29.1 of prime95.exe

1) 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.
2) 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.
3) AVX-512 trial factoring support added.
4) Dialog box for benchmarking added.
5) 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.

Downloads Views Developer Last Update Version Size Type Rank
3,159 4,566 Mersenne Prime Search <img src=""border="0"> Mar 28, 2017 - 11:31 29.1 5.73MB ZIP 5/5, out of 1 Votes.
File Tags
Prime95  64bit  29.1  
Download Time
56Kbit Modem:  14m 19s  · 256Kbit:  3m 8s  · 1Mbit:  47s  · 5Mbit:  10s

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