Prime95
From Free net encyclopedia
Template:Infobox Software Prime95 is the name of the Windows-based software written by George Woltman that is used by GIMPS, a distributed computing project dedicated to finding new Mersenne prime numbers. The Linux-based version is called MPrime.
Prime95 can be downloaded for free.
Use for stress testing
Over the years, Prime95 has become extremely popular among PC enthusiasts and overclockers as a stability testing utility. It includes a "Torture Test" mode designed specifically for testing PC subsystems for errors in order to help ensure the correct operation of Prime95 on that system, but can also be used to stress test a PC. People who are overclocking their system may use the torture test as an indication of the stability of their system.
Although it is hard to judge precisely how many people use Prime95 as a stability test, the adoption is almost universal. Most, if not all of the overclockers and people who want to make sure their computer is completely reliable are using or have used Prime95 in the past. Template:Fact
The stress-test in Prime can be configured to better test various components of the computer by changing the fast fourier transform (FFT) size. Three pre-set configurations are available: Small FFTs, In-Place FFTs, and Blend. Small and In-Place modes primarily test the FPU and the caches of the CPU, whereas the Blend mode tests everything, including the memory.
By selecting Custom, the user can gain further control of the configuration. For example, by selecting 8-8KB as the FFT size, the program stresses primarily the CPU. By selecting 2048-4096KB and unchecking the "Run FFTs in-place" checkbox, providing the maximum amount of RAM free in the system, the program tests the memory and the chipset. If the amount of memory to use option is set too high then system will start using the paging file and the test will not stress the memory.
On an absolutely stable system, Prime95 would run indefinitely. If an error occurs (the tray icon will become yellow from the default red), there is a chance that the system is unstable. There is an ongoing debate about terms "stable" and "Prime-stable", as Prime95 often fails before the system becomes unstable or crashes in any other application.
In the overclocking community a rule of thumb is often used to determine how long to run Prime95: test the CPU (8KB FFT) for 10 hours and the memory (4096KB FFT) for 10 hours, and if the system passes, there is a high chance that it is stable.