Resolved Memory Slots Showing As Empty?

Discussion in 'Mac Pro' started by The Buggman, Oct 26, 2013.

  1. The Buggman, Oct 26, 2013
    Last edited: Oct 26, 2013

    The Buggman macrumors member

    Joined:
    Oct 25, 2013
    #1
    Hello All,

    I recently upgraded to OS X 10.9 before installing 2x2GB of memory into my Early 2008 Mac Pro which would make for a total of 10GB RAM.

    The configuration involves splitting the original 2x1GB – one on each side and into slot 1 – with the new 2x2GB memory in slots 2 and 3 on each side.

    However, for some reason, as I check my total RAM, it shows as only having 6GB of memory. Additionally, as I check System Information, the second memory slots for both sides are showing as empty.

    Is this something I've caused with my configuration or would this entail a bigger issue? I have included a screenshot to show my problem. DIMM2 in Riser A and B should both be showing and additional 2GB.

    http://i.imgur.com/FYv7aLD.png
     
  2. photographypro macrumors regular

    photographypro

    Joined:
    Jul 7, 2010
    Location:
    American in Pisa (Italy)
    #2
    move the chips

    Moving the "empty" chips to different slots. If they show as "empty" in their new locations, they're probably bad.
     
  3. The Buggman thread starter macrumors member

    Joined:
    Oct 25, 2013
    #3
    I've tried swapping the sticks already. If there's nothing of which I'm unaware that would cause these slots to show as empty in this configuration, I can only imagine the slots themselves are bad. But, it's a little too coincidental.

    Both of the second slots on each side certainly wouldn't suddenly go bad. Also, both 2x2GB sets of RAM were purchased separately. The original set occupies one side and the new set occupies the other.

    I could try moving the sticks from slots 2 into slots 4. Would that cause any unforeseen troubles?
     
  4. westrock2000 macrumors 6502

    Joined:
    Oct 18, 2013
    #4
    Attaching working image

     

    Attached Files:

  5. westrock2000 macrumors 6502

    Joined:
    Oct 18, 2013
    #5
    When I first got my Mac it had 2x512MB and 2x2GB and I tried the same thing you are doing to see how the risers worked and the same thing happened. In my case I did 2GB+512MB on each side.

    You have to keep like values as pairs. So put one pair of 2x2GB on each side. And then put the 2x1GB on one side (doesn't matter which). It should work after that.
     
  6. DanielCoffey macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #6
    According to Apple on http://manuals.info.apple.com/MANUALS/0/MA430/en_US/MacPro_Early2008_MemoryDIMM_DIY.pdf

    So you will want 2 + 2 + 1 + 1 and 2 + 2 + empty + empty
     
  7. The Buggman thread starter macrumors member

    Joined:
    Oct 25, 2013
    #7
    Thanks to all who replied.

    After trying several different configurations with various results (going from showing 6GB to 3GB to 6GB and then to 8GB), I believe I have determined that the original 2x1GB are no longer compatible with the extra 2x2GB in place. I now have 2x2GB on each riser.

    None of the memory is corrupt, but I believe I must retire the original 2x1GB and settle on 8GB of total memory instead of the desired 10GB... (unless I end up with a second pair of 1GB sticks to even out each side). Thanks again for your assistance.
     
  8. DanielCoffey macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #8
    Did you follow the illustration for which slots to use when you have 6 dimms?
     
  9. The Buggman thread starter macrumors member

    Joined:
    Oct 25, 2013
    #9
    I did. I know the sticks to be functioning, but the 2x1GB were failing to be recognized. I'll definitely try again in a bit, however. I cannot remember if they were occupying slots 1 & 2 or 3 & 4. Perhaps that will be what makes the difference[?].
     
  10. DanielCoffey macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #10
    It should, yes - the guide was quite specific.
     
  11. The Buggman thread starter macrumors member

    Joined:
    Oct 25, 2013
    #11
    Well I would love to have come back and said how there's no way it was my fault. I would have mentioned how the guide fails to speak of the importance of size order in the risers' slots and spoke of how I, alone, outsmarted the machine in triumphant determination.

    Unfortunately, none of this is true. There is no importance to size order when pairing the slots on the risers. The blunder was my own. In my early-morning ineptitude, I did not fully regard the difference between Riser A and Riser B. Thus, the issue has been resolved as provided by the obligatory RTFM platitude.

    Thank you for your persistence and devotion to the matter, DanielCoffey.
     

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