Mac Pro Ram Pairing Question

Discussion in 'Mac Pro' started by iranintoavan, Jan 22, 2008.

  1. iranintoavan macrumors regular

    iranintoavan

    Joined:
    May 3, 2005
    #1
    First off I know there are lots of RAM questions and that you will probably say "search!!!" Well I did and I couldn't find a clear answer so heres my quick and simple question.

    I have the first revision of the mac pro and I have the stock 1 gig of ram (2x512). I am looking at getting either 2(2x1gig) or 4(2x2gig) from OWC. Now I know that you have to buy in pairs for max speed (if that's the right term). Does this mean I would be fine having in one ram riser 2 pairs of different sizes such as (2x512mb) and (2x2gig)? Thanks for all the help.
     
  2. CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #2
    Have a look in the MR Guide to Installing RAM

    It's fine to have a pair of one size alongside a pair of another size. The gains from 256 bit access (by installing 4 identical) are minimal.
     
  3. swingline macrumors member

    Joined:
    Aug 9, 2005
    #3
    I kind of have the same question but I've already installed 2x1gb ram along with the stock 2x512 ram. It feels pretty slow and the boot up time sucks.
     
  4. CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #4
    Well, if you installed it per Apple's diagram, your slowness is not due to the extra RAM -- unless you have some defective RAM... What are the Recoverable ECC errors standing at in Activity Monitor?
     
  5. iranintoavan thread starter macrumors regular

    iranintoavan

    Joined:
    May 3, 2005
    #5

    Ok so let me get this right. At the moment I have (2x512) in A1, A2. If I ordered 4gigs (2x2gig). I should re-arrange it to be, (2x2gig) in A1, A2 then the old (2x512) in B1, B2?

    Thanks for giving me that link and helping!
     
  6. CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #6
    Yes.

    Theoretically, there should be no difference between A1 A2 and B1 B2, but it's just easier to remember - start with your largest RAM in A1 A2 and work your way from there.
     
  7. iranintoavan thread starter macrumors regular

    iranintoavan

    Joined:
    May 3, 2005
    #7
    Thank you very much, that cleared everything up!
     
  8. KeithBrofsky macrumors newbie

    Joined:
    Mar 16, 2012
    Location:
    Bainbridge Island, WA
    #8
    Mixed Combo & What's the Max?

    Hi Mac Friends,

    I have a question... leave it me to complicate things!

    I run a Mac Pro, Early 2009 quad core with 2x 2.93 GHz.

    I had 6 sticks of RAM at 1 gig each. I do pro photography and now video, and its been bogging down. Time for RAM.

    I thought I read that 16 gigs is all it can handle (?) so I bought 3 sticks of 4 Gigs each, and kept 5 of the 1 gig sticks. I put them in order as recommended on the handy popup guide. Its running better, but I wonder if I shouldn't have another 4 gig stick to match the Mis-paired duo (4 & 1).

    4. 1
    4. 4
    1. 1
    1. 1

    Also, I bought a 2 Tb hard drive and wondered if I should make it my primary starter disc, or make it a scratch disc instead. Its worth noting I use a 1 Tb drive as my Time Machine, but I can't use TM for all the photo files. Those are on a Drobo with 8.8 TB installed.

    Thanks so much for your knowledge and kindness in sharing it in kind.

    Keith
     
  9. bsbeamer macrumors 6502

    Joined:
    Sep 19, 2012
    #9
    Believe max RAM for that machine per is 16GB x 6 (six sticks of 16GB RAM) for a total of 96GB. If wanting to use all available slots, you can go 8GB x 8 (eight sticks of 8GB RAM) for a total of 64GB.

    Not sure what I'd recommend with the mix & match system you have going. I've had had issues with pre-2010 machines and mixing RAM sets.
     

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