Can I do 3GB in a unibody MBP?

Discussion in 'MacBook Pro' started by Gryfon19, Feb 18, 2009.

  1. Gryfon19 macrumors regular

    Jun 27, 2007
    Is there any reason I couldn't replace one of the 1GB stick in my MBP with a 2GB to make it a total of 3GB? Or does it have to be symmetrical (i.e. if I put in one 2GB, I have to put in two)? Thanks.
  2. Minimoose 360 macrumors 65816

    Minimoose 360

    Jul 7, 2008
    It doesn't have to be symmetrical, but there are performance gains with "dual channel" RAM (ie. having two equal sticks). 3GB is still better than 2GB though if I am not mistaken. Personally I would say go to 4GB (2X 2GB) as it's pretty cheap now.
  3. InLikeALion macrumors 6502a

    Jul 18, 2007
    Greener places than I used to live
    Having enough ram to not have page-outs to your hard disk will drastically improve your performance. Gaining dual channel would have a minimal performance increase. I'm running 3 gigs in my uMBP right now until the 4gb chips drop below the $200 mark. And then, I'll have 6gb total, which traditionally wouldn't have dual channel.

    However, I also remember about 9 months ago someone linking to whitepapers for upcoming (now available) intel chipsets which could retain dual channel with mismatched ram sizes. Perhaps the nVidia Ion platform incorporates this? Either way, more ram for me trumps dual channel.
  4. NightSailor macrumors 6502


    Feb 24, 2008
    Dual Channel versus More Memory

    It is an interesting question.

    For example: I've been thinking about this question in regards to my nieces Uni MacBook which presently has 2GB.

    Going from 2 GB to 3 GB, avoiding Page-Outs would be the driving factor. It makes sense to upgrade to 4 GB and avoid the question.

    However, going from 4 GB to 6 GB (the Maximum), when Page-Outs are less likely to occur, I am wondering whether the extra RAM is a smart choice. If you load up your machine with a lot of applications, then the 6 GB is the smart choice. If you don't then 4 GB makes sense. I[ll probably install 4 GB soon and wait on going for more as the prices are fairly high now for 4GB DDR3.

    It would be nice if a MacBook could be loaded up with 8GB of RAM, once the prices drop, and programmed not to use the last 2GB if there is a limitation, or else opened up to allow the full 8GB or RAM--allowing the benefit of dual channel speeds with the extra capacity to avoid slow page-outs.
  5. Gryfon19 thread starter macrumors regular

    Jun 27, 2007
    How many slots does the uni MBP have? I was thinking two...but now I could be wrong.
  6. PeterQC macrumors 6502a


    Jun 30, 2008
    Only 2. While Nehalem in a few months might have 3.
  7. Gryfon19 thread starter macrumors regular

    Jun 27, 2007

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