30.19.20 CPU stress testing app for Windows

Sven Sorensen

Software to test the performance and stability of a CPU by running complex mathematical calculations.

Freeware prime numbing software download, reviewed by Sven Sørensen
Program specially designed for users who want to search for various Mersenne Prime numbers - Screenshot of Prime95
Comparison with other similar apps - Screenshot of Prime95
Torture Test - Screenshot of Prime95
Performance - Screenshot of Prime95
Powerful  and efficient software - Screenshot of Prime95
Can find Mersenne Prime numbers. Stress CPU - Screenshot of Prime95

An extensive CPU stress test diagnostic which searches for prime numbers, execute Lucas-Lehmer primality test.

Prime95 is a bench-marking application used to test the power of your CPU, or processor.

The utility of this program is great, putting your CPU to the test by finding prime numbers, numbers which are only divisible by 1 and themselves. This is a great idea for pushing a CPU to its limits by harnessing its processing power.

By using Prime95 on a system, you'll find an excellent tool to test the performance level and stability of a CPU and by extension, a PC.

As on of the top choices for overclocking enthusiasts and system tweakers, Prime95 is a good companion to heat up your PC and testing its limits by running it under experimental conditions, such as upping the clock rate and voltage. It can be ultimately useful to test whether cooling fans or water-heating are sufficient for high-powered gaming setups.

The Torture Test feature of Prime95 is the best way to put your processor and memory to the test. This mode will run a succession of tests: Small TTS, In-place large FFTs and Blend. The latter being the most intensive of the three tests. Passing these tests means the PC is ready to go, but keep in mind that it could take an entire day for Prime95 to do its magic.

As with any type of PC stress test, you should keep an eye on the target system and the temperatures.

As a freeware tool, Prime95 competes with other applications like IntelBurnTest or CPU Free Benchmark but has come to be the gold standard. An online community of overclockers and other enthusiasts exist where users of Prime95 can share their test results with the wider world.

All in all, Prime95 serves as the gold standard in system stress testing and bench-marking, making it an essential companion to anybody wishing to test the stability of their system setup.

Features of Prime95

  • CPU stress testing: Prime95 is known for its ability to stress test a computer's central processing unit (CPU) to ensure it's functioning properly and can handle demanding tasks.
  • Compatibility with overclocking: Works with overclocking, making it a useful tool for enthusiasts who want to push their hardware to its limits.
  • Continuous testing: Run the stress test continuously, allowing users to test the stability of their system over a long period of time.
  • Customizable test options: Customize the stress test by adjusting the test duration, number of threads and memory allocation.
  • Detailed reporting: Provides detailed reporting, including the test duration, number of errors found and CPU usage during the test.
  • Error checking: The software includes a feature that checks for errors in the CPU and memory while the stress test is running.
  • In-depth analysis: Provides in-depth analysis of the stress test results, including information about the stability of the system and any errors that may have occurred.
  • Monitoring hardware parameters: Able to monitor hardware parameters, such as CPU speed, voltage and memory frequency while the stress test is running.
  • Multi-thread support: Supports multi-threaded testing, which allows users to test multiple threads at once, increasing the accuracy of the stress test.
  • Real-time graphs: Includes real-time graphs that display the CPU usage, temperature and other hardware parameters during the stress test.
  • Save and load test configurations: Users can save and load test configurations for future use, making it easy to run the same test again at a later time.
  • Temperate monitoring: Allows users to monitor the temperature of the CPU and other components to prevent overheating.
  • Test specific parts of the CPU: Allows users to test specific parts of the CPU, such as the floating-point unit or integer unit.
  • Torture test: Includes a "torture test" mode that runs an intensive stress test for an extended period of time to find stability issues.
  • Workload distribution: Uses intelligent algorithms to distribute the workload across multiple cores and threads, ensuring an accurate stress test.

Compatibility and License

Prime95 is provided under a freeware license on Windows from benchmark software with no restrictions on usage. Download and installation of this PC software is free and 30.19.20 is the latest version last time we checked.

Mersenne Research accepts donations for the continued development of this free software.

What version of Windows can Prime95 run on?

Prime95 can be used on a computer running Windows 11 or Windows 10. Previous versions of the OS shouldn't be a problem with Windows 8 and Windows 7 having been tested. It comes in both 32-bit and 64-bit downloads.

Filed under:
  1. Prime95 Download
  2. Free Benchmark Software
  3. Prime Numbing Software
Prime95 has been picked by our editors as very good.
Prime95 has been tested for viruses and malware.
We have tested Prime95 30.19.20 against malware with several different programs. We certify that this program is clean of viruses, malware and trojans.