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, which effectively stress-tests a PC.
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.