Need advice for upgrading RAM in MBP and MB.

Discussion in 'Buying Tips and Advice' started by Turian.Spectre, Oct 6, 2010.

  1. Turian.Spectre macrumors regular

    Turian.Spectre

    Joined:
    Aug 31, 2010
    #1
    I own a MBP bought january 2010 with 4gb ram.

    Also own a white MB bought january 2010, and another white MB I will buy next weekend. I think they are still selling the same intel models.

    SO I thought maybe I could upgrade my MBP memory to 8, by buying a package of 2 x 4GB. Then use my 2 x 2GB sticks that I am replacing and put each one into the MBs, thus upgrading both of those to 3GB instead of the original 2.

    Is that possible? Are they the same size? Same type? Would they be recognized? I am a noob in all this and I have no idea which ones to buy, also from where, and whether my sticks from MBP will be compatible with the MBs. As far as installation, nothing Youtube cant fix. Help?!
     

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  2. Intell macrumors P6

    Intell

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    Jan 24, 2010
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    Inside
    #2
    Yes you can do this. But if you have an unmatched pair of ram stick it could slow your machine down a bit. Example one 4Gb and one 2Gb stick is slower then two 2Gb sticks.
     
  3. Turian.Spectre thread starter macrumors regular

    Turian.Spectre

    Joined:
    Aug 31, 2010
    #3
    OK. well the MBP will be matched 2 X 4GB. the ones in the MB will be different b/c I am substituting them. Why would it be slower? even if they were made by the same company? makes no sense to me. Im use to thinking more=better. =/
     
  4. Intell macrumors P6

    Intell

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    #4
    Its called double data rate or DDR (2 or 3), think of it like a highway. A two lane highway can take so many cars. But a four lane can take twice as many. The matched is like a four lane highway. So people don't see a noticeable difference.
     
  5. Turian.Spectre thread starter macrumors regular

    Turian.Spectre

    Joined:
    Aug 31, 2010
    #5
    ooooh. so having a 2 lane going 1 way and a 1 lane the other is no good then. =(((

    sucks. well maybe i will upgrade My MBP like i said with the 2x4GB and use my replaced 2x2gb to put into one of those MBs. At least that should work without an issue right?

    do you know which I need to buy? and where?
     
  6. Batt macrumors 65816

    Batt

    Joined:
    Dec 17, 2007
    Location:
    Syracuse, NY
    #6
    Unless you're doing rocket surgery or brain science, I doubt you'll notice any possible slowdown. Go with your original plan. More RAM is always better, matched or not.
     
  7. nitro912gr macrumors member

    Joined:
    Oct 3, 2010
    Location:
    Athens, Greece
    #7
    I completely disagree with that.
    First of all the problem will be with the dual channel in memory, it works with pairs of 2 dimms of the same size, same timings etc.
    This way the system doesn't have to wait for dimm 1 to fill up with data, but it is using the 2 dimms alternately, storing data faster on both at the same time. This is not 100% more speed, but it is giving about ~60% more speed in data exchange.

    On the other hand the compatibility issues that may appear between the 2 different dimms does not make a suitable option to use them together. It is most likely that there will be system fails because of this memory configuration.
    I have learned it the hard way by trying to use a much safer configuration, where I used 2x1 GB same dimms, with another 2x512MB dimms on the same system. It popped up BSOD from nowhere (windows system, but OS doesn't have to do anything with this, at this problem) because of the incompatibility with the RAM dimms, even if they where in 2 pairs of same dimms.

    So I suggest to thread starter to add the 2x2GB to one the whites, and use the other one with 2x1GB as it comes.
     
  8. Hellhammer Moderator

    Hellhammer

    Staff Member

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    Finland
    #8
    Very few apps can really take advantage of the extra memory bandwidth that dual-channeling offers thus it's very unlikely that OP would notice any difference between single- and dual-channel. Besides, more memory should offer better improvement in performance than dual-channeling.

    Modern memory controllers are fine with mismatched modules. Some years ago, it was important to install them in pairs or you would face issues but luckily that's history.
     
  9. nitro912gr macrumors member

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    Oct 3, 2010
    Location:
    Athens, Greece
    #9
    Every app benefits from that, I don't know how or why you believe the opposite, if there was no benefit from that then why to get faster and faster RAMs in the market and even introducing the newer triple channel RAMs with the i7s?

    I don't know what are these modern controllers you are talking about, but even in a just bought mobo for AMD CPU, I read on the manual that, user must not use different dimms. And everyday I read about compatibility problems because different RAM dimms on other hardware forums.
     
  10. Batt macrumors 65816

    Batt

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    Dec 17, 2007
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    Syracuse, NY
    #10
    There is a benefit to more RAM. Period.
     
  11. Hellhammer Moderator

    Hellhammer

    Staff Member

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    Dec 10, 2008
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    Finland
    #11
    http://www.tomshardware.com/reviews/PARALLEL-PROCESSING,1705-11.html
    http://www.tomshardware.com/reviews/PARALLEL-PROCESSING,1705-12.html
    http://www.tomshardware.com/reviews/PARALLEL-PROCESSING,1705-13.html

    Little to no gain. In basic usage like Safari and Mail, there is no noticeable difference.

    SOME people do benefit from the extra bandwidth but as I said, there are only handful of apps that can benefit form such memory bandwidth. Most of use would still be fine with 667MHz DDR2 and 2GHz Core 2 Duos but that doesn't stop companies from improving their products as SOME people need the extra speed. RAM speeds are a marketing trick nowadays, it doesn't impact average Joe's usage.
     
  12. Turian.Spectre thread starter macrumors regular

    Turian.Spectre

    Joined:
    Aug 31, 2010
    #12
    Thats what I decided to do. One question left unanswered. which should I buy? and from where?
     

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