2GB or 2.5GB... Does dual channel matter?

Discussion in 'Buying Tips and Advice' started by Samwise592, Oct 25, 2007.

  1. Samwise592 macrumors regular

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    #1
    So I've got a choice to make... with Leo arriving at my door in under 24 hours, i realized that I'm gonna need 2gb of ram to make it preform like it should, but now I've got a choice:

    1.) Buy a 2gb stick and replace one of my 512 sticks for a total of 2.5GB (Not dual channel)
    2.) Buy a 2gb kit (2x1gb) and run dual channel....

    which one will give me better performance?
     
  2. killerrobot macrumors 68020

    killerrobot

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    #2
    Buy the kit 2X1 kit.
    Yes, running dual channel makes a big difference.
     
  3. jsw Moderator emeritus

    jsw

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    #3
    It all depends on how much RAM you need. If you almost never exceed 2GB in use, dual-channel is marginally faster.

    If you exceed 2GB of memory needed, non-dual-channel RAM is overwhelmingly faster than virtual memory disk swapping.
     
  4. twoodcc macrumors P6

    twoodcc

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  5. jsw Moderator emeritus

    jsw

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    #5
    In the C2Ds, yes, IIRC.
     
  6. Samwise592 thread starter macrumors regular

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    #6
    You have to be able to put a 2gb stick in a MacBook... how else could you reach its 3gb limit?
     
  7. flopticalcube macrumors G4

    flopticalcube

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  8. twoodcc macrumors P6

    twoodcc

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    #8
    my bad, i thought you could only put 3GB in the MBP.
     
  9. twoodcc macrumors P6

    twoodcc

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    #9
    after looking at Apple's website, it says the macbook only goes to 2GB?
     
  10. Eidorian macrumors Penryn

    Eidorian

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    #10
    The current Core 2 Duo model goes to 3 GB. The same with the Mac mini.
     
  11. twoodcc macrumors P6

    twoodcc

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    #11
    ok. you just have to do it yourself?

    what happens if you try 4GB?
     
  12. bigus7674 macrumors member

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    #12
    iMac C2D RAM question

    Ok, so here's a question I've been pondering: the iMac C2D (pre-aluminum models) can theoretically have 2 x 2GB modules inserted but will only really use 3.3GB of the RAM (approx. 700 MB will be "lost" due to hardware limitations).

    So, question is, what is better....to have 2 x 2GB modules installed and lose the 700MB but have dual-channel support (if it will even support it on this configuration) or to just have the 1 x 2BG, 1 x 1GB setup for a total of 3GB (max) and mis-matched pairs without dual-channel?
     
  13. Eidorian macrumors Penryn

    Eidorian

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    #13
    Yes, it's aftermarket only.

    On the 4 GB front, it'll either say there's 4 GB but only be able to use 3-3.25 GB or it just won't boot at all.

    Just go with the 3 GB.
     
  14. flopticalcube macrumors G4

    flopticalcube

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    #14
    Of course the dual channel, but it costs more.
     
  15. samh004 macrumors 68020

    samh004

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    #15
    It's marginal.

    You can put two in, it's just not worth it.

    I use 2.5GB RAM in my MB C2D 2.16

    It only addresses 3.3GB and if you address more than 3.3GB, or you are hitting the limit, you face instability. Kernel panics etc...
     
  16. Eidorian macrumors Penryn

    Eidorian

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    #16
    Eh?

    The memory addressing isn't a software issue.
     
  17. 119576 Guest

    119576

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    #17
    If you try 4GB, your MacBook will recognise (and take advantage of) 3.3GB
     
  18. samh004 macrumors 68020

    samh004

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    #18
    There was a thread on here, a forum user put 2 x 2GB sticks in a MB and said that it saw 4GB. Everyone asked questions and the end result was when the computer used as much RAM as possible it became unstable because it hit the limit and threw a wobbly.

    Use search to find it, I have no idea where it is now, but it's here... somewhere.
     
  19. Samwise592 thread starter macrumors regular

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    #19
    so... since that got totally off topic...

    will my performance be better with 2gb of dual channel, or 2.5gb with mismatched ram?

    ...Before you ask, i normally have Firefox(4-10 tabs), iTunes, iChat, transmission, a few finder windows, and sometimes MS word open. (a few dashboard widgets as well)
     
  20. Eidorian macrumors Penryn

    Eidorian

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    #20
    You'll be better off with more RAM.

    I remember quite a few threads like that but I don't remember the instability being software based.
     
  21. flopticalcube macrumors G4

    flopticalcube

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    #21
    If you are not using all of the 2G than 2X1 will be faster.

    LOL! Nice to see two opposite answers to the same question! Now I hope that settled it for you. :D
     
  22. Eidorian macrumors Penryn

    Eidorian

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    #22
    I noticed that.

    Even Barefeats admits you're better off going with more RAM then strictly with dual channel.

    I can get the links if you want.
     
  23. samh004 macrumors 68020

    samh004

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    #23
    I was/am in exactly the same situation. I have a 2GB module and a 512MB module and I couldn't be happier, they both run at the same temperatures and it's smoother than when it was just 1GB matched.

    I never said it was software based, but I can see how you'd get that conclusion, all I said was that it had instabilities and kernel panics. For all I know that could be paranormally based :p

    I'm just repeating what I read in the thread. Now I'm going to bed. :p
     
  24. Eidorian macrumors Penryn

    Eidorian

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    #24
    Same situation back on my iMac G5. I'm glad I had 1.5 GB instead of 1 GB.


    I blame solar flares.
     
  25. flopticalcube macrumors G4

    flopticalcube

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    #25
    It really depends if the OP is even going to reach the 2GBs with his current use. I think the bump from 2 to 2.5 is not a whole lot. If you are going to start swapping at 2, then you probably will be at 2.5 as well.

    Samwise592: check to see how much blue and green is left in Activity Monitor.
     

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