The RAM is arguably the most important part of your computer. Apart from the processor, of course, but without some kind of memory, even the process is pretty much useless. A computer, without RAM, cannot run any application that you tell it to and might as well be a dead paper weight.
If you’ve noticed unusual freezes and random operating system/application crashes on your computer, the RAM should be your first line of diagnosis. The RAM on a modern computer is composed of millions of cells that store the data for the computer to process and failure of even a single cell can cause weird errors that can be extremely difficult to diagnose.
Memtest is an open source utility that verifies the RAM installed on your computer for any defects. Since, this is an open source tool, there are versions available for practically every operating system and I’m going to use the Mac OS X version of memtest today since that is what I’m most familiar with. You should be able to use the same command line switches with the version of memtest available for your operating system.
Download MemTest For Free
Memtest is available as a free download so just download it to your computer and unzip the file. You should now have a .pkg installer that you can just double click to install memtest. This installer does nothing other than installing the memtest binary to /usr/bin.
To start testing the RAM on your computer, launch Terminal.app and execute memtest.
Sharninders-iMac:~ sharninder$ memtest all 1
The above command will make memtest run through it’s complete test suite once. In general, it is better to test at least twice, or even let it run for a few hours if you want to be completely sure. If you don’t specify any number after the “all”, memtest runs indefinitely and will have to be stopped by pressing the ctrl+c key combination manually.
If Memtest throws up an error or memtest itself freezes, you’ll know for sure that the RAM is bad. If not, well, time to start diagnosing other parts of the computer.
Memtest for PCs
If you’re not running a Mac, you can still use memtest to diagnose the RAM of your PC, though the process is a little different. For PCs, memtest is distributed as images that you can burn onto CDs or USB flash drives.
Download one of the many pre-built images and burn it to a CD or to a USB flash drive, depending on the image. Now, shutdown your computer and reboot it using the CD/USB Key that you just burned. That should start Memtest straight away. Let the diagnostics run for a while or till you’re sure that the RAM has been tested thoroughly.
Have you ever had the RAM in your computer go bad ? How did you diagnose it ?