Memtest86

Memtest86 is a free application run from a boot disk, designed to stress-test your computer’s RAM for errors. It will work with most x86 based computers.

• To create a bootable CD-ROM, download the ISO image here and burn to CD with your choice of burning software.

Ideally, Memtest should be run on only one memory module at a time, to aid in troubleshooting. If you have more than one RAM module in your computer, remove all but one and run Memtest on each module separately.

Running Memtest is as simple as putting your boot disk into your PC, changing the boot priority in your computer’s BIOS, and rebooting. The default configuration is sufficient for most users. Memtest will run automatically, and you will see something similar to the screenshot below.

Memtest will run through a series of tests, reporting on overall progress, progress through the current test, overall time takes for testing and number of passes made, and any errors encountered (errors are reported in red). It is a good idea to let it run through several passes. The time it takes to complete each pass depends on the amount of RAM you have, it’s speed, and your CPU speed. There are ten tests in all - to stop testing, remove your boot disk and reboot your computer.

Most of the time, errors reported indicate a faulty RAM module, and steps should be taken to replace it. If you are unsure, create a thread in the forums.

Note: On some very rare occasions, Memtest can get confused about the amount of memory available and try to test memory that does not exist. This will result in a large number of errors appearing in consecutive addresses, with a large number of error bits. This does not necessarily indicate a faulty RAM module, unless you are also getting errors at other memory addresses.

In addition to helping diagnose faulty hardware, Memtest can be used to test memory that has been overclocked. Generally, overclocked ram which is going to fail a test will fail test #5, so many users will initially run only this test (several times). It is prudent to run the full suite of tests before assuming the ram is at a Memtest-stable overclock.

Note that Memtest tends to be easier to pass than the traditional Windows-based tests, such as Prime95.

Memtest86+ is based on the original Memtest86, but is better maintained, with bug fixes and support for newer chipsets/processors. The interface is essentially the same, so anyone familiar with Memtest86 should have no problems transitioning to it.