Memory upgrade config questions for a 2008 iMac

Discussion in 'iMac' started by slobizman, Feb 22, 2013.

  1. macrumors member

    Jun 16, 2008
    I've got an early 2008 iMac with 2GB memory (1+1), and want to upgrade it, as I'm having a few issues running iPhoto and iMovie, plus a few other things, well. My target was 4GB of memory, as 6GB gets a bit expensive for an aging computer.

    So, my options are:

    (all are PC6400 DDR2 800MHz)

    1) Replace memory with 2GB + 2GB (~$60)
    2) Replace memory with one 4GB (~$70)
    3) Replace one 1GB memory module with a 4GB module, leaving 4GB +1GB. (~$70)

    What would be my best choice? In particular, does option #3 have any issues -- would it be better than option #2?
  2. macrumors Westmere


    May 16, 2008
    There is a slight performance benefit in using matched pairs of RAM, such as 2x2GB.
    MR Guide to Matched RAM on Intel Macs
  3. thread starter macrumors member

    Jun 16, 2008
    Thanks, I understand that.

    But that doesn't mean that the 2GB x 2GB config would be better than the single module 4GB config would it?

    And if it's not, and I do get the single 4GB module, does adding the 1GB module to the second slot actually slow down the 4GM module?
  4. macrumors Westmere


    May 16, 2008
    Yes, it would be somewhat better. That's what the article I linked describes.
    If the pairs are not matched pairs, it doesn't matter what configuration they are.
  5. macrumors 6502a

    Sep 2, 2008
    Metro Kansas City
    I have an early 2008 iMac with 6GB. Although I lost the small speed improvement due to dual channel when putting in unmatched sticks, I gained dramatically in reducing page outs. If you don't want to spend the money for the full 6GB, I'd go for the 5GB as I have found that Mountain Lion coupled with iMovie consumes the majority of the RAM, leaving little free for anything else.
  6. macrumors 6502a

    Apr 30, 2008
    USA (Virginia)
    My 24" Early 2008 iMac is running 6 GB, and I've been very satisfied and had no issues. Currently on 10.8.5.

    If I were you I'd go with the 5 GB (4+1) over the 4 GB (2+2), for the $10 difference. My guess is that the extra 1 GB would be more valuable more often than the 3% or 6% performance lost. But it's just a guess.

    I don't think you'll run into any problems, since the machine handles the (4+2) case so well.

    Good luck!

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