Early 2010 iMac - can I add 2 x 4gb modules to make it 12GB?

Discussion in 'iMac' started by dealmaker, Nov 19, 2010.

  1. dealmaker macrumors regular

    Sep 24, 2010
    So my early 2010 iMac has 8gb of memory (4 x 2GB modules).

    I happen to have 2 spare 4gb modules that are from a MacBook pro of the same era - i.e they are DD3 1066Mhz and they will fit.

    So question is - if I take out two of the 2gb modules and replace them with 2 of the 4gb machines - will the machine work and will it see the full 12gb ( 2 x 2gb plus 2 x 4 gb)?

  2. iDutchman, Nov 19, 2010
    Last edited: Nov 19, 2010

    iDutchman macrumors 6502a

    May 9, 2010
    Amsterdam, NL
    Early 2010? That means before the summer, so it's the 2009 revision.

    The 2009 revision uses 1067Mhz, so you'll be good on that one.

    You can always use 2 x 4GB sticks to add 8Gb to the already existing 4GB, making it a total of 12GB. I also did this with my mid 2010 iMac.

    Although, there is one drawback in your story.

    The MacBook Pro uses the PC-8500 RAM while the iMac uses the PC3-10600 RAM.

    So, that won't do. :rolleyes:

    EDIT: I hear the Pro's saying it will work despite the difference in name.
  3. TMRaven macrumors 68020


    Nov 5, 2009
    The 2010 iMac uses 1333mhz ram while your 09 macbook uses 1066mhz ram.

    The memory controller on the iMac will downclock the 1333mhz ram to 1066mhz accordingly, so you won't have any problems.
  4. rkaufmann87 macrumors 68000


    Dec 17, 2009
    Folsom, CA
  5. iDutchman macrumors 6502a

    May 9, 2010
    Amsterdam, NL
    So, maybe you could answer my question then.:D

    I recently installed 2x 4Gb to the already existing 2 x 2GB for a total of 12GB RAM in my iMac mid 2010 27".

    Now, does it matter where I put the new sticks? I just left the old ones and added the new ones to the empy slots. Is that wrong?
  6. Hellhammer Moderator


    Staff Member

    Dec 10, 2008
    It's fine. I think that's the way how new RAM should be installed anyway
  7. richpjr macrumors 68030


    May 9, 2006
    I just updated my iMac that way (added 2x4 in the empty slots). I did read somewhere after the fact that it was better to put the larger ram in the slots that the 2x2 ram ships in but things are working fine and I have been too lazy to go back and do it.
  8. dealmaker thread starter macrumors regular

    Sep 24, 2010
    Well - I simply pulled out two of the 2GB modules and put in the 2 4gb modules I have.

    Booted up machine and I now have 12GB - machine is noticeably faster :D (I wasn't really expecting to notice much difference if I'm honest!)

    Hooray for Apple - every time I've tried anything like this in the past on a PC (mixing memory sizes / even manufacturers) its resulted in the Blue Screen of death! :apple:
  9. jlyanks85 macrumors 6502a

    Jan 3, 2008
    What's the brand of ram that apple has installed in the imac already? I'm thinking of getting more ram too when my imac gets delivered to me on Wednesday, and don't want to buy a different brand where it won't work.
  10. WilliamG macrumors G3

    Mar 29, 2008
    It shouldn't matter. I bought Crucial sticks for my iMac. It's probably Hynix/Samsung stuff in there already. I just added another 2x2GB Crucial to my iMac for 8GB in dual channel mode since 12GB supposedly won't accomplish that, and it's worked swimmingly since January. :)
  11. TMRaven macrumors 68020


    Nov 5, 2009
    12gb should work with dual channel, you just theoretically need to put a 2gb and 4gb module in each bank, making 2 banks of 6gb total.
  12. George Knighton macrumors 65816

    George Knighton

    Oct 13, 2010
    So...pardon my stupidity...but....

    Does a "bank" run left to right, or up and down?


    Got new 12GB on the way and don't want to put it in wrong.
  13. Vividjelly macrumors newbie

    Oct 11, 2010
    Hey everyone,

    I finally pulled the trigger and ordered my new Imac. After reading through the advice on the forum, I went for a SSD instead of the extra RAM, and bought some 2x4GB from Crucial :D

    This thread has already answered one of the questions I was going to ask, but does it matter which slots I add the extra 2x4GB RAM I've got coming, performance wise?

    I will be looking at buying 2x4GB in a month or so anyway (once my bank balance recovers from the 2500 grand its spent :eek:), but it would be nice to know in the meantime.

    Thanks :p

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