Macbook Pro (late 2011) 16GB RAM Upgrade Startup Crash

Discussion in 'MacBook Pro' started by directflight, Jul 7, 2012.

  1. macrumors newbie

    Joined:
    Jul 7, 2012
    #1
    I ordered 16 GB of ram (2x8GB) for my macbook (late 2011 13in 2.4 core duo), installed it and the machine boots up but eventually freezes on the apple screen with the boot spinner. I spent some time googling to no avail, so maybe someone can offer some assistance here.

    After the usual, reseating the ram, etc, I was able to boot into a DVD based linux distro and run mem test and use the system in text mode without any issues... until... I ran startx to start the graphical interface which leads me to think it is a video card/driver issue.

    I booted into single user mode, and again, I'm not sure, but I believe that the system freezes when it changes into a different video mode. I couldnt' find any info anywhere on this happening.

    Eventually I installed one 8GB card and one of the original 2 GB cards. OSX boots flawlessly with 10 GB ram. I'm really stumped as to how this could work. I had a theroy that perhaps since the new ram is rated 1333 Mhz and is presently running at 1067Mhz that maybe the older chip forces a lower speed on the more capable chip and that while the logic board can handle the full 16 GB mem, it glitches with the video card at a higher speed?

    This is all speculation. If anyone has any suggestions, I would greatly appreciate it.
     
  2. macrumors 6502a

    user418

    Joined:
    Aug 22, 2010
    #2
    Try running the Apple Hardware Test. The Apple Hardware Test (AHT) contains a suite of diagnostics that will test the hardware of your computer. It's a great way to rule out a hardware issue when troubleshooting your computer.
     
  3. thread starter macrumors newbie

    Joined:
    Jul 7, 2012
    #3
    I wanted to update this thread in case anyone else has the same issue. After a bit more testing I've confirmed this to be an issue with the GeForce 320m integrated video in the 13 Macbook Pro. Apparently it needs the ram to run at 1066/1067mHz while the logic board supports the 1333mHz memory and will run it at that speed when installed. This causes a glitch and freezes the computer. This explains how the computer can run in a low graphic mode.

    My work-around / hack is to run two mis-matched ram cards, a 1333mHz 8GB card and a 2GB 1066/1067mHz card. This results in the board underclocking the faster chip to 1067mHz and therefore working. As far as I can tell there is no way on the macbook to underclock the ram and I have been unable to locate any 1067mHz pc3 8gb ram.
     

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