Free Memory Test

When you attempt to boot your computer does it answer you back with a series of cryptic beeps? Does your PC randomly shutdown at in opportune times and for no apparent reason? Are you occasionally greeted with a blue screen and white typeface that posts an indecipherable message, or a screen that grossly distorts images which normally render nicely?

If you answered “yes” to one or more of these questions then your computer’s memory may be slipping.

(Before proceeding, let us first clear up what we mean by “memory” and briefly describe the vital
role it plays in the function of computing devices. “Memory” is a generic term for Random Access Memory {RAM}, and is a form of short-term data storage. In essence, RAM serves to “juggle” the multiple tasks you ask your computer to perform while powered on, allowing for faster performance. When your computer is powered off those tasks are no longer in use and any data you have saved is written to your device’s long term storage–a hard disk drive (think vault)–for use at a later time.

While problems with RAM can be difficult to diagnose, one easy-to-use, no cost option for testing memory you suspect of being faulty is Memtest86. This valuable tool can be made to boot from a floppy disk (if you can find one), a CD or DVD (remember those?), a flash drive, and over a network via PXE boot.

To use Memetest86, first download an ISO or USB image of the most recent version available (currently 4.0a) for either Linux or Windows and create a bootable CD, floppy, or flash drive. Next, enter your device’s BIOS and configure the boot device order to correspond to the bootable device you just created.

Once running, Memtest86 will give you the option of running in one of two modes: basic and advanced. While advanced mode is comprehensive, we find it to be more-time consuming than necessary for the average user, and as such recommend running the diagnostic in basic mode. As you run the basic test, any errors in RAM will appear at the bottom of your screen in red highlighted blocks.

So how does Memtest86 work? In essence, the program writes a series of test patterns to RAM, reads back the pattern, and compares the two for errors. If the pattern can not be written, if the pattern read does not match the pattern written, or if the pattern written can not be read, the diagnostic will return errors.

If Memtest86 returns an error, chances are very good that you have bad RAM. Your next step should be to power down your computer, disengage it from its power source, remove the faulty RAM module, and return it to either the retail outlet you purchased it from or directly to the manufacturer. Insist on an even exchange. Most retailers and manufacturers will honor the exchange if the request is made within the warranty period. The picture can get a bit murkier if your RAM is out of warranty, however.

One last thing (actually two):

If you are dealing with multiple RAM modules, it makes sense to remove the additional modules from the motherboard’s memory banks and test each module individually in the same memory bank. Label each module that passes the test with e.g. a sticker so as not to get confused.

It is possible to have a bad memory bank on your motherboard, in which case all the modules you test will display errors. You can switch to a different bank if this happens with all the RAM you are testing.

Don’t forget Memtest86 the next time you suspect bad memory!