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Using 3 RAM slots instead of 4

851 Views 4 Replies Latest reply: Sep 29, 2011 1:04 AM by MacZwik RSS
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Sep 28, 2011 7:57 AM



My iMac (bought in april 2010) came with 2 x 2 Gb of RAM. Today I received a 4 Gb RAM and I put it in the empty slot of my iMac. I was wondering if it is ok to use only 3 slots instead of the 4 the iMac has.


I was also wondering if I use the right order for the RAM:



BANK 1/DIMM0: 4 Gb (I put it in there today)


BANK 0/DIMM1: 2 Gb (Has always been there)

BANK 1/DIMM1: 2 Gb (Has always been there)


Best regards

iMac 21,5, Mac OS X (10.7.1)
  • noisyneighbor Level 1 Level 1 (10 points)
    Currently Being Moderated
    Sep 28, 2011 8:14 AM (in response to MacZwik)

    Hi MacZwik,



    The above models support Nonparity RAM configuration, which means it is ok to leave one of the slots empty.

    I personally prefer installing RAM of the same brand though. Hope this helps


    check out HT1423 for more info



  • noisyneighbor Level 1 Level 1 (10 points)
    Currently Being Moderated
    Sep 29, 2011 12:20 AM (in response to MacZwik)

    "It is not working better if the first slot has the 4gb the second is empty and in 3 and 4 the 2gb's"

    --- are you saying that the computer seem faster when the 4GB stick is in the first slot?

    Check (Apple Logo > About this Mac ) if the added RAM is recognized, 4GB to 8GB is a huge jump and you should be able to "feel" the difference.


    You can also check About this Mac > More Info> System Report  to see if the 4GB stick is recognized when placed on any of the slots.









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