Download Prime95 - a handy tool for overclockers and system stability checkers, Prime95 has a feature called "Torture Test" that allows maximum stress testing on the CPU and RAM. There are several options allowing the stress test to focus on the memory, processor, or a balance of both.

Usually Prime95 will detect an error within a matter of minutes if an overclock is not stable, however many people like to let the system "burn-in" overnight to ensure long-term stability. FPrime95 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

• Support added for AVX-512 FFTs.
• FMA3 FFTs now have slightly higher FFT crossover points. Soft crossovers are
• no longer used by default. See undoc.txt.
• Torture test dialog box options now based on cache sizes. Options for performing
• a weaker torture test are available. Torture tests that use all RAM are now more
• stressful. In-place vs. not in-place memory accesses now displayed on screen.
• On machines with more than 5GB of memory, blend defaults to all but 3GB of RAM.
• Add & subtract operations for AVX-512 FFTs are now multithreaded. This should
• improve performance for P-1 and ECM when using multiple threads.
• Benchmark results are now written to results.bench.txt.
• JSON results are now available for all work performed. JSON results are
• written to results.json.txt.
• PRP tests with Gerbicz error checking are more immune to hardware errors.

The benefit of this version is that it is multi-threaded and will automatically manage worker threads to fully stress all cores of your CPU.