Prime95
 Prime95 icon in its "on" state | |
| Developer(s) | George Woltman |
|---|---|
| Initial release | 3 January 1996 |
| Stable release | 30.19 build 13[1]
/ March 7, 2024 |
| Preview release | 30.19 build 14[2]
/ March 30, 2024 |
| Written in | ASM,C |
| Operating system | Microsoft Windows,macOS,Linux,FreeBSD |
| Type | Mersenne primefinder / system stability tester |
| License | Freeware[3] |
| Website | mersenne |
Prime95,also distributed as the command-line utilitymprimeforFreeBSDandLinux,is afreewareapplicationwritten byGeorge Woltman.It is the official client of theGreat Internet Mersenne Prime Search(GIMPS), avolunteer computingproject dedicated to searching forMersenne primes.It is also used inoverclockingto test for system stability.[4]
Although most[5]of itssource code is available,Prime95 is notfree and open-source softwarebecause itsend-user license agreement[3]states that if the software is used to find a prime qualifying for a bounty offered by theElectronic Frontier Foundation,[6]then that bounty will be claimed and distributed by GIMPS.
Finding Mersenne primes by volunteer computing
[edit]Prime95 tests numbers for primality using theFermat primality test(referred to internally as PRP, or "probable prime" ). For much of its history, it used theLucas–Lehmer primality test,but the availability of Lucas–Lehmer assignments was deprecated in April 2021[7]to increase search throughput. Specifically, to guard against faulty results, every Lucas–Lehmer test had to be performed twice in its entirety, while Fermat tests can be verified in a small fraction of their original run time using a proof generated during the test by Prime95. Current versions of Prime95 remain capable of Lucas–Lehmer testing for the purpose of double-checking existing Lucas–Lehmer results, and for fully verifying "probably prime" Fermat test results (which, unlike "prime" Lucas–Lehmer results, are not conclusive).
To reduce the number of full-length primality tests needed, Prime95 also implements other, computationally simpler tests designed to filter out unviable candidates; as of 2021, this mainly comprisesPollard's p – 1 algorithm.Theelliptic-curve factorization methodandWilliams's p + 1 algorithmare implemented, but are considered not useful at modern GIMPS testing levels, and mostly used in attempts tofactormuch smaller Mersenne numbers that have already undergone primality testing. Prime95 implementstrial division,but because this type of work can be executed usingsingle-precisionarithmetic (as opposed to thedouble-precisionarithmetic required by other GIMPS work types), almost all GIMPS trial division is done by third-party clients implementingGPUcomputation for its comparatively much greater single-precision throughput.
GIMPS has discovered 17 new Mersenne primes since its foundation in 1996, all using Prime95.[8]Each was thelargest known prime numberat the time of its discovery, except M37156667and M42643801,which were discovered out of order from the larger M43112609.[9]
Use for stress testing
[edit]
To maximize search throughput, most of Prime95 is written in hand-tunedassembly,which makes its system resource usage much greater than most other computer programs. Additionally, due to the high precision requirements of primality testing, the program is very sensitive to computation errors and proactively reports them. These factors make it a commonly used tool amongoverclockersto check the stability of a particular configuration.[4]
See also
[edit]References
[edit]- ^"GIMPS - Free Prime95 software downloads - PrimeNet".mersenne.org.Archivedfrom the original on 2023-02-03.Retrieved2023-02-04.
- ^Woltman, George (2023-10-04)."mersenneforum.org - View Single Post - ECM users - version 30.9-30.18 (see post #465 & #398)".mersenneforum.org.Archivedfrom the original on 2023-10-27.Retrieved2023-10-27.
- ^ab"GIMPS Legalese - PrimeNet".Great Internet Mersenne Prime Search.Retrieved2019-05-08.
- ^ab"How To Run a CPU Stress Test Using Prime95".Appuals.2015-12-10.Retrieved2019-05-23.
- ^Woltman, George."The security code or checksum is hard to forge. This is the only source code that is not published".
- ^"EFF Cooperative Computing Awards".Electronic Frontier Foundation.2008-02-29.Retrieved2019-05-08.
- ^Woltman, George (2021-04-08)."First time LL is no more".
- ^"GIMPS History - PrimeNet".Great Internet Mersenne Prime Search.Retrieved2019-05-09.
- ^"GIMPS Milestones".mersenne.org.Retrieved2021-10-17.
External links
[edit]- Official websitewith downloads for various architectures
- How to use Prime95 for stress (torture) testing[1]
- ^"Torture test your CPU with Prime95".playtool.Retrieved2022-09-15.