The 6 Best Free Programs for Stress Testing Your PC

Your build is complete, but can is it cut out for the job?

Build complete, but can it handle the stress?

Very few things in life are more satisfying than assembling all the parts to a new PC, hitting the power button, and watching it boot up properly.

But even if your build starts up and seems to work without problems, you might want to make sure all the components are fully functional. Does your graphics card pump out pretty pictures at the level promised by the manufacturer? Does your RAM operate consistently for hours on end? Does your CPU process the desired number of ones and zeroes under intense loads without overheating?

To answer these questions, we turn to stress testing: Making sure that all of your parts can handle the work that they’re designed to do (or overclocked to do). They might be fine under normal use, but you want to know that they’ll be able to handle heavier tasks down the road, such as high-end gaming or media editing.

With stress testing, we simulate a heavy processing load on the entire computer or a particular component in order to identify potential weak points, faulty hardware, or a need for better cooling.

Before you begin

Stress testing is done with specific testing software. And the whole point of this article is to recommend software, so we’ll get to that in a second. First, some advice before getting started:

  • For best results, you want your PC to focus all of its energy on the tests. Close all non-essential programs.
  • Stress testing is usually done over long periods of time. Make sure to adjust your power settings to disable sleep mode before you start testing.
  • Stress testing can be potentially dangerous for your components. Most components are designed to shut off before incurring damage, but it’s better to be safe than sorry. We recommend getting some type of hardware monitor software, such as HWMonitor, to keep tabs on temperatures.
  • Once you have hardware monitoring software, look up the maximum temperatures for your CPU and GPU. Most CPUs should not exceed 70 degrees C, and most GPUs should not exceed 100 degrees C. If your components surpass their maximum heat, or stay close to the maximum for extended periods, stop the stress test.

With that out of the way, let’s look at some of the best software for torturing your PC:

CPU testing

Prime95The most popular free software for testing CPUs. It will run indefinitely, and shut off if it finds a problem. It’s recommended to run Prime95 for at least 3 hours, and to make sure temperatures don’t get too dangerous while you’re testing. [Instructions for using Prime95]

IntelBurnTestAnother popular option for testing CPUs. IntelBurnTest uses the same stress-testing engine that Intel uses internally for quality control before shipping out CPUs. The program also claims to perform the necessary tests in 8 minutes, as opposed to 3+ hours with Prime95.

For a slightly more obscure option, there’s also Super PI, a single-threaded benchmark that calculates the number pi up to a specified number of digits (with a maximum of 32 million). It’s not the ideal stress test for multi-core CPUs, but it can still give you a good idea of how your PC will handle single-threaded tasks. It’s also not a bad frame of reference for PC gaming performance.

GPU testing

FurMarkAn extremely popular graphics stress test. This program should push your graphics card harder than even the most demanding game on the market. If your GPU has problems, you should know within about 15 minutes.

Unigine’s ValleyAnother popular GPU stress test. This test renders out an extremely detailed nature scene to see how much your graphics card can handle.

Unigine's Valley stress test

Unigine’s Valley stress test

RAM testing

MemTest86The definitive RAM test. Boots from a USB drive or CD/DVD to test everything about your RAM. If something turns red, that’s bad. Otherwise, you’re good.

And that’s it. What stress testing programs have you found to be the most useful? Did we miss anything? Let us know in the comments, and good luck torturing your PC.

If you’re looking for help building the PC that you’ll eventually torture with these stress tests, check out our latest custom PC build recommendations on our homepage at