Comments on: Testing RAM on a Macbook Pro

By: Geo

Geo — Sat, 16 Nov 2013 17:27:30 +0000

I bought PNY brand 8 GB kit (4GB x 2, ) because it was the only UNOPENED one that was in stock locally. Ran MEMTEST overnight. A-OKAY.

The “Mid-2009” and “Mid-2010” MacBook Pro models support 1066 MHz PC3-8500 DDR3 SO-DIMMs and officially and unofficially support a maximum of 8 GB of RAM, spec: 204-Pin DDR3 SO-DIMM DDR3 1066 (PC3 8500) Laptop Memory.

During the next few days, the MacBook Pro crashed or froze several times, randomly.

So, I ran the MEMTEST in single user mode overnight, three passes, and it failed on pass 3.

Returned the PNY brand and ordered online from Crucial. They offer a 45 day refund and lifetime exchange, which is much better than any local store offered.

By: James

James — Mon, 18 Feb 2013 16:36:40 +0000

Thanks! This helped!

By: anon

anon — Mon, 11 Feb 2013 22:18:49 +0000

hi, I was able to get into the single mode but when I type the memtest all, nothing works.. it’s days command not found

By: Cleber

Cleber — Sun, 10 Feb 2013 20:21:08 +0000

It is possible, however unlikely, that you might have a RAM problem in the area that doesn’t get tested by the app (there is generally a small portion that doesn’t get tested). If you are comfortable opening up your MBPro, try swapping the sodimms (put the lower one on the top slot and vice versa). Of course, use static electricity and other usual precautions when handling the memory cards. Of course, that is assuming you have 2x2GB sodimms and not just one 4GB stick.

I have found in a couple of cases that this has led to errors being found. Might be worth a try.

By: Maurits

Maurits — Thu, 31 Jan 2013 23:08:11 +0000

I have MacBook Pro 15 inch 2011 with 4 gb of RAM. My Mac crashes often after I quit a game like minecraft. After a start up it beeps 3 times with a pause and then 3 beeps again. I think it’s something with the RAM but I when I run memetest it doesn’t come up with anything and I also tried apple hardware test and no trouble found either. I have a windows partition on my Mac and it runs smoothly, no crashes even playing games like minecraft and just cause 2. If it is a RAM problem how come it only affects my Mac partition?

By: Shawn M. Jones

Shawn M. Jones — Tue, 11 Dec 2012 02:17:44 +0000

Dillon (elsewhere in comments) cleaned out the slots and reset the PMU switch. You could try that.

By: dell

dell — Fri, 07 Dec 2012 06:04:08 +0000

Hi,
Sorry for the trouble, i realised it later after i posted it,Anyways i managed to install it and checked both my memory sticks Individually as well as together, both the time it passed all the tests, but still whin i turn on my laptop after its been shutdown for quite some time it starts giving the three beeps at start up and wont boot, then you just remove the ram and put it back again and it works fine, then i tested it with just 1 slot populated and it works fine with both the ram cards, then i populated both the slots with the original ram that came with the laptop and it works fine with out any problem.
Now im confused both my 4gb rams works fine individually both my slots on the mother board work fine, bu somehow both the 4gb ram together dosent seem to work whereas they used to work without any problems before.
Any sugestions.

Thankyou once again.

By: Shawn M. Jones

Shawn M. Jones — Thu, 06 Dec 2012 04:00:13 +0000

The memtest utility doesn’t come with OSX. In the article, I state “I had to install memtest”, and link to where you can get a packaged copy of it: http://www.command-tab.com/2008/01/11/how-to-test-ram-under-mac-os-x/

If you can’t boot the mac, it will be difficult to put memtest onto the Mac. Good luck.

By: dell

dell — Fri, 30 Nov 2012 20:46:29 +0000

Hi,
Im having a late 2011 mac pro 13″ i5 with 8 gb ram installed and running mountain lion on it, lately i’ve been facing problems such as it boots up to an grey screen with three beeps, then when you try to boot it up again after two or three attempts it boots up fine and workes fine without any problem untill the next time i boot it up after a few hours.
Now i followed your instructions for the memtest, but at the prompt when i enter memtest all it returns saying the the command does not exist, iv’e tried uname -m just to make sure it runs in 64 and it returns x86_64.
Can you suggest what might be the problem, please…

Thanks,

By: Shawn M. Jones

Shawn M. Jones — Thu, 22 Nov 2012 15:00:57 +0000

If it gets stuck on the MEMTEST, then I’d say it’s highly probable that you’ve got bad RAM, or the motherboard is having issues.

If you have more than one stick, try MEMTEST on the sticks one by one. If you have one stick, try buying another one (you can likely return it if you find out that’s not the problem).

Also, you are running this in single-user mode, without the GUI running, right? Single-user mode reduces the number of processes that are running in the background. If you’re not running the MEMTEST in single-user mode, then a runaway process may be making your Mac sluggish. An i7 MBP with 8GB of RAM should not be sluggish.