Mac RAM Troubleshooting

When things start going “wonky” (tech term) on your Mac, you need to determine if the problem is software or hardware related. Think of it as two paths, you are either going down the software troubleshooting path or the hardware troubleshooting path. One thing that causes hardware issues is failing RAM. Albeit, not a very common problem these days, but it still happens at times.


There are several symptoms of RAM problems. Here is a partial list:

  1.  3 Beeps at Startup indicates bad RAM on your Mac
  2. Bad Graphics on your Mac
  3. Screen Pausing
  4. Application Crashes
  5. Data Corruption
  6. Kernel Panics

I know, pretty scary right. Bad RAM used to be more prominent in the “old days” of Mac and PC computing. It is not such a problem these days, but it can still rear its ugly head. If you are having any of the above issues it could be bad RAM. It might be other things as well. If you wish to troubleshoot this kind of behavior then you need to eliminate RAM as the cause. A good way to do that is to download and run a little App called Memtest. This App is labeled as free, but you can pay a developer donation of $1.49 via PayPal.

When you download Memtest, the .dmg file opens into a folder containing the following stuff:

Memtest Folder

I almost forgot, you have to enter a pass code that is provided to you when you first open the .dmg file. Just drag the whole folder into your Applications folder.

The actual application is a Unix Executable file. When you double-click the file, it runs its routines automatically. It is running in the Terminal Application. Here is the App running some of it’s tests:

Memtest Testing

In case you were wondering, I have no clue what all the tests actually stand for or do. But, I can tell you, this App is nothing but thorough. I ran the tests on my iMac, and it took about an hour to complete. It might be a good idea to run it while you are away from your Mac, at dinner or running some errands.

There is another thing I want to mention. The Memtest folks tell you it is best to run the App in “Single User Mode” because it can do a more thorough test of the RAM components. If you prefer to run it in “Single User Mode” here are their instructions from their User Guide:

Memtest is best run in OS X’s single-user mode. In this mode, nearly all of the installed ram can be tested whereas under the full OS, a considerable portion of memory is tied up by OS X processes and the Quartz window manager. Running memtest in single-user mode maximizes the effectiveness of the memory test.

To boot into single-user mode, hold down the “Command” and “S” keys during startup. You will be automatically logged in as the user root with a minimal command line environment. The login directory for the root account is “/” which is the top-level directory of the boot volume. Assuming that the memtest folder resides in your Applications folder, a typical invocation of memtest would be the following:

> /Applications/memtest/memtest all 3 -L <RETURN> ( <RETURN> means press the Return key)

I think running the App in a booted up Finder is sufficient. I am sure if you have some bad RAM it will alert you.


To troubleshoot Mac problems you need an arsenal of good Utility Apps. Memtest should be in that list. At a whopping $1.49 there really is no reason not to have it.