2x1GB + 4x2GB = 10GB

Discussion in 'Mac Pro' started by brand, Mar 26, 2008.

  1. brand macrumors 601

    brand

    Joined:
    Oct 3, 2006
    Location:
    127.0.0.1
    #1
    My new mac pro was delivered yesterday and 4x2GB of RAM, from OWC, was delivered today at work. Since I am not at home where my Mac Pro is I am wondering what is the proper way to install the 4x2GB and the 2x1GB modules.
     
  2. Tallest Skil macrumors P6

    Tallest Skil

    Joined:
    Aug 13, 2006
    Location:
    1 Geostationary Tower Plaza
    #2
    Top riser: 2GB 2GB 1GB 1GB
    Bottom riser: 2GB 2GB
     
  3. TEG macrumors 604

    TEG

    Joined:
    Jan 21, 2002
    Location:
    Langley, Washington
    #3
    Riser A
    2GB
    2GB
    1GB
    1GB

    Riser B
    2GB
    2GB
    ---
    ---

    I used to think that each riser had to be even, but reciently read the new MacPro Manual and you install each matching pair in A0/1, then B0/1, then A2/3, and then B2/3.

    TEG
     
  4. irwanation macrumors newbie

    Joined:
    Mar 12, 2008
    #4
    Congrats. I received m OWC 8GB kit this morning as well. I used the same arrangement as stated by others above. Runs perfectly. Enjoy.
     
  5. mgsarch macrumors regular

    Joined:
    Jan 19, 2008
    #5
    Weird, I could have sworn I did A:2,2,2,2 B:1,1.

    I followed the instructions that came with the OWC RAM and i remember thinking: yeah, that makes sense, Apple on one board, and OWC on the other.

    Maybe I'm just lapsing.

    Everything been working very nicely for over a week though.
     
  6. c:\windows macrumors member

    Joined:
    Feb 27, 2008
    Location:
    Houston, Texas
    #6
    I did the same a2.2.2.2 b1.1

    I will benchmark it then switch the configuration and post the results.
     
  7. Thiol macrumors 6502a

    Thiol

    Joined:
    Jan 26, 2008
    #7
    OWC and Barefeats suggest 2:2:1:1 and 2:2. That's what I have now...
     
  8. mgsarch macrumors regular

    Joined:
    Jan 19, 2008
    #8
    Thank you, I look forward to it. It will take significant gains for me to pull open the case! It's my workstation, if it ain't broke I gotta stop trying to fix it!
     
  9. benpatient macrumors 68000

    Joined:
    Nov 4, 2003
    #9
    I set mine up A: 2,2,2,2 B: 1,1

    My first instinct was to do A: 2,2,1 B: 2,2,1 but I ready somewhere (can't find it now) that it would be faster as I've set it up...I'd like to see the results of A: 2,2,1,1 B: 2,2 as a comparison...can't find on barefeats...
     
  10. c:\windows macrumors member

    Joined:
    Feb 27, 2008
    Location:
    Houston, Texas
    #10
    I tried it with 4 different configurations and it really looked the same.... It is probably randomness in xbench that accounts for the slight differences. I left the config a2211b2200. These results mean anything to anyone?
     

    Attached Files:

  11. DrRock macrumors regular

    Joined:
    Jun 18, 2005
    #11
    If nobody minds me hijacking..

    I just received 8 1GB sticks from OWC for my dual 2.3 G5.

    I wanted to max out, so I was wondering; can I remove the factory installed sticks (2x256mb) and simply put all the OWC sticks in? Or is there some reason I need to keep the Apple Ram?

    OWC salesman said I could, but I wanted to be sure. Thanks!
     
  12. pastrychef macrumors 601

    pastrychef

    Joined:
    Sep 15, 2006
    Location:
    New York City, NY
    #12
    Yes, you can take out the Apple RAM.
     
  13. CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #13
    No, definitely slower the way you set it up.

    Two reasons:
    1) You have defeated Quad channel access which requires the first 2 slots on each riser to be equally populated

    2) The higher (3rd and 4th) slots have a higher latency because all accesses to them are mediated first through the first and second slot RAM, which has to evaluate the request and forward it.

    You want to have the majority of your RAM in the first 2 slots so you spend as little time as possible accessing the 3rd and 4th slots.

    Your configuration puts 40% of your RAM in the slow slots.... sorry :eek:
     
  14. DrRock macrumors regular

    Joined:
    Jun 18, 2005

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