Real world drawbacks to using the 4th RAM slot on MP 2010?

Discussion in 'Mac Pro' started by curvephotograph, Sep 22, 2010.

  1. curvephotograph macrumors member

    Joined:
    Jun 18, 2010
    #1
    I ordered a 12 gb kit and have been given a free upgrade to 16gb because they didn't have the 3 piece module in stock. So my question is will using the 4th slot on my MP quad 2010 to have 16gb of RAM installed be more beneficial than keeping it tri channel and 12gb?
     
  2. Hellhammer Moderator

    Hellhammer

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    Dec 10, 2008
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    Finland
    #2
    Only very few apps can take advantage of the extra memory bandwidth that tri-channel offers. The extra 4GB of RAM will likely be better improvement than tri-channel
     
  3. yoink macrumors member

    yoink

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    Feb 17, 2008
    Location:
    Montreal, Quebec
    #3
    From what I've read (which could be wrong) there's only a negligible performance hit. I'm under the impression that the system will only share the final channel with the 4th slot if it "needs" the memory and at that point the memory will come in more handy than the triple channel speed boost.
     
  4. Whaditis macrumors regular

    Joined:
    May 18, 2010
    #4
    I was wondering the same thing as well. Thanks for the info.

    I started with the octo 2009 Mac pro being 6 gb ram (6x1gb sticks)

    Now I picked up in addition 2 x 2gb modules and put them in slots 1 and 5 while moving the 1gb sticks to slots 4 and 8 which are the final 4th slot for each cpu.
    So that's 10gb now and it appears it is better off to have more ram than less in tri-channel.

    Glad that this has been determined.

    Does anyone know if using the 4th slot means that only the ram in that slot is single channel but the other 3 slots remain tri-channel or do all slots become single channel?

    Thanks
     
  5. Hellhammer Moderator

    Hellhammer

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    #5
    IIRC, both pairs will run in dual-channel configuration
     
  6. curvephotograph thread starter macrumors member

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    Jun 18, 2010
    #6
    Thanks Hellhammer, I use lightroom 3 and PS5 so its a safe guess neither will use tri channel if they have'nt exactly embraced muti core :cool:
     
  7. Whaditis macrumors regular

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    May 18, 2010
  8. Ozric macrumors newbie

    Joined:
    Jul 22, 2004
    Location:
    NJ
    #8
    While we're on this topic, would it make a difference if on a 12 core system, I had different amounts of memory equally distributed, for example, 2 X 4GB in slots 1&5, 2 X 2GB in slots 2 & 6, 2 X 1GB in slots 3 & 7, etc...
     

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