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How to Test RAM: Making Sure Bad Memory Isn't Crashing Your PC

how to test ram

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Your computer's RAM is key to its operation. Explained simply, RAM is your computer's short-term memory, which it uses to work on its current task. However, like any computer part, even the best RAM can break, so you'll want to know how to test whether your memory is stable or not. 

One of the first signs of memory going bad is blue screens of death (BSODs). Memory issues often make themselves easily noticeable by their rapidly increasing severity. At first, you'll only rarely experience crashes, and the system will still be workable. But before you know it, the system will crash during start-up. Therefore, it's important to identify the problem quickly.

There are multiple ways of testing your computer's memory. We'll cover a few of them today. 

How to Test RAM

how to test ram

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One option preferred by us at Tom's Hardware is HCI Design's MemTest . The good thing about this is you don't have to any pre-booting and there are no directions. You just run it. 

How to Test RAM With Windows Memory Diagnostic Tool

The next easiest way to test your memory is with Windows 10's built-in Memory Diagnostic tool. 

1. Search for "Windows Memory Diagnostic" in your start menu, and run the application.

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2. Select "Restart now and check for problems." Windows will automatically restart, run the test and reboot back into Windows.

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3. Once restarted, wait for the result message. This may take a few moments to appear as the system starts up. Be patient. It will show up, but keep an eye out for it, as it will disappear again quickly. 

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How to Test RAM With Passmark Memtest86

PassMark's Memtest86 is a reliable tool for testing memory without the need for an operating system, meaning it will work on Windows machines as well as Linux computers. It runs off a bootable USB stick, and although it looks complicated, it is very straightforward to use.

1. Download Passmark Memtest86.
2. Extract the contents into a folder on your desktop.
3. Insert a USB stick into your PC. Back up any data on it, as Passmark's tool will format the USB stick.
4. Run the "imageUSB" executable.
5. Select the correct USB drive at the top, and press 'Write'

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6. Double-check whether everything is correct before proceeding. Writing will take a few moments, depending on the speed of your USB stick.
7. Restart your computer, and enter the boot menu through pressing F2, Del, F8, F10 or whichever key your system uses. It will say on your post screen.
8. Boot off the USB stick.
9. Press "Config."

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10. Select "(S)tart Test" in the Memtest86 home screen.

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Now let the application run the test until completion or until errors appear. You can monitor the progress of the test at the top of the screen.

Depending on your memory size, testing can take from 20 minutes to a few hours. If errors appear, there is no point in continuing testing. A screen with errors looks like this:

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What If My RAM Is Bad? 

If you didn't get any errors: congratulations. Your memory is in working order. You can either rest assured or, if you are having crashes, continue troubleshooting to figure out what else may be the cause now that RAM issues are ruled out. 

If you do get errors, then also congratulations: you've found the culprit of your crashes. In 95% of cases, the only way to fix memory issues is to buy new RAM or replace it. If you have multiple RAM kits, be sure to test them independently to figure out which is causing problems and send it in for warranty. Luckily, a lot of RAM kits come with a lifetime warranty these days.

But there are three things you can do to try to get rid of these RAM-caused issues. 

The first is to ensure that your RAM is running at the correct clocks for your system. All memory has its speed and timings written on its label or packaging, and you want to make sure that it runs at these speeds using the XMP profiles in your BIOS. It hardly ever happens, but it's possible that the memory was set to run faster than it was capable of, which would naturally lead to errors.

If setting the right XMP profile in your BIOS doesn't help, another trick that sometimes works is to underclock your memory -- i.e. run it slower than the intended speeds. You can do this by reducing the frequency and backing off on the timings. However, this is often a temporary measure because if the RAM has degraded, the errors are likely to return soon.

Lastly, note that certain platforms do not play nicely with all memory configurations. If you're running an especially high memory frequency, be sure to check whether this is supported by your CPU and motherboard. Out-of-spec combinations will make it appear like the memory is broken, when in actuality the memory controller on your CPU is unable to handle the RAM's high frequencies.

Niels Broekhuijsen is a Contributing Writer for Tom's Hardware US. He reviews cases, water cooling and pc builds.