How do I check my memory??? AHT?

Discussion in 'Mac OS X Lion (10.7)' started by Crunch, Dec 31, 2011.

  1. Crunch macrumors 6502a


    Jun 26, 2008
    Crazy L.A.
    I just installed my 2x8GB RAM chips for a full 16GB of memory in a 2011 MacBook Pro. It's recognized and it shows up everywhere (System Information/Profiler, About this Mac, 3rd party tools, etc.)

    However, in Lion, there is no more holding down the "D" key to run diagnostics and searching around revealed that there may be a .diagnostics folder that needs to be copied from the Recovery HD partition but I couldn't find it anywhere. (and yes, I did mount the "Recovery HD" and unhid the system files)

    Then I came upon an app called "Rember", which is basically a "prettified" memtest with a GUI. I tested a couple of gigs and everything tested fine (while already having more than 9GB worth of applications and other stuff open). When I did the "ALL" function, I came across an error after a long time, but I don't necessarily trust that result, because it may not be compatible with Lion.

    So...basically, I'd really like to check out my RAM to see if it's good. I'm a bit paranoid because Apple doesn't "want you to put in more than 8GB", but I could really use at least 12GB, but I'd prefer the full 16GB. Apple says to copy .diagnostics from the discs. What discs??? I'm totally fine with the whole no more optical drives but don't refer to disks that you never put in the package, :apple: !?? I just want to (stress)test the heck out of my RAM...:confused:
  2. dumb macrumors member

    Nov 1, 2009
    Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3)

    i tried to run AHT on my new MBP with lion and read article about how to do it on Lion. The apple KB is basically useless.

    Instead of holding D, try holding Option D. Worked for me everytime.

    edit: provided you have internet connection.
  3. Mal macrumors 603


    Jan 6, 2002
    AHT doesn't do a particularly good job of stressing the RAM, actually. It's a good cursory check, but if you really want a good test, try Rember. You'll need to enable the root account and run it from there with nothing else open, so dedicate some time to it, but it will do a very good and extensive check of the RAM.

  4. Crunch thread starter macrumors 6502a


    Jun 26, 2008
    Crazy L.A.
    Sweet! Yup, works just fine, like you said. Thanks, man! Everyone else had me jumping through all kinds of hoops as I stated in my original post when it was super simple. Thank you again! :)

    Yes, I did try Rember actually, as I said before, but only a few GB and not as the root user.

    By the way, how do you guys feel about the Extended memory test that's part of AH? It sees each 8GB chip but under the manufacturer name, it just says 0x000. 16GB is going to take several hours, right? I guess I'll put it on before I go to bed or something. Is the current version of Rember officially Lion-compatible as far as that it won't miss anything, and, by the same token, produce an error somehow due to something having to do with Lion?

    Anything else I might want to try/consider?

    Thanks to both of you for some super fast and great insight. This 16GB thing is working pretty well so far and it just screams. The price is just crazy. How could 16 gigs be so dirt cheap when it was prohibitively expensive in the $1,200+ area only a few weeks ago? Holy :apple: :apple:

    P.S.: Do you think that RAM manufacturers are really going to slow down production in order to raise prices? Any thoughts or precedents I should know about? Thanks again!

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