Prime95 – Free Professional CPU Benchmarking Test

Today's computers are not perfect, and it is unlikely they will ever be perfect. Even brand new systems from major manufacturers are having hidden flaws. If any of several key components such as CPU, memory, cooling, etc. are not up to spec, it can lead to incorrect calculations, freezes, and/or unexplained system crashes.

Overclocking is the practice of increasing the speed of the CPU and/or memory to make a machine faster at little cost. Typically, overclocking involves pushing a machine past its limits and then backing off just a little bit.

For these reasons, both non-overclockers and overclockers need programs that test the stability of their computers. This is done by running programs that put a heavy load on the computer. Though not originally designed for this purpose, this program is one of a few programs that are excellent at stress testing a computer.

Prime95 has been a popular choice for stress / torture testing a CPU since its introduction, especially with overclockers and system builders. Since the software makes heavy use of the processor's integer and floating point instructions, it feeds the processor a consistent and verifiable workload to test the stability of the CPU and the L1/L2/L3 processor cache. Additionally, it uses all of the cores of a multi-CPU / multi-core system to ensure a high-load stress test environment.

Generally, an uninterrupted 6 hour run of Prime95 indicates that the CPU is good and will not have issues over its usable lifetime. However, it’s important to ensure temperatures are kept in a reasonable range.

There are several options when using Prime95 to stress test the CPU. The most intense test is the Small FFTs stress test which stresses the CPU the most ensuring that any possible issues will reveal itself early on. Another good test is the blended test which not only stresses the CPU, but the RAM as well. If you’re limited on time, this is a good way to test both the CPU and RAM at the same time.

The CPU benchmarks can be accessed: https://www.mersenne.org/report_benchmarks/

Warning

While running Prime95 your CPU will become incredibly hot, it is imperative that you keep a constant watch of your CPU temperature with a system monitoring utility such as Speccy, Speedfan or HWMonitor. If your CPU temperature does reach dangerous levels stop the Prime95 stress test to prevent inflicting damage on your CPU.

The application was written by George Woltman and is used by GIMPS, a distributed computing project dedicated to finding new Mersenne prime numbers.

Cost: Free

Website: https://www.mersenne.org/download/