Tutorial for adding RAM to 8 Core Mac Pro

Discussion in 'Mac Pro' started by Technoracle, Dec 10, 2008.

  1. Technoracle macrumors newbie

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    Dec 10, 2008
    #1
    Having just spent 4 hours playing around with adding 8 GB of RAM to an 8 Core Mac, largely thanks to the useless and misleading information given to me by a service rep at a local store, I ended up making a small tutorial in hopes of saving some people time. I posted step by step instructions here
    since I could not find any articles that were very well documented, not even via Apple.com (caveat - they probably exist, I just couldn't find them). If any of you plan to do the same, you might want to read this. The local Mac store technies didn’t know this.

    http://technoracle.blogspot.com/2008/12/mac-pro-8-core-ram-not-recognized.html

    Hope this save you time and angst.:cool:

    Question: does anyone know why these complex matchings exist?
     
  2. Horst Guest

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    #3

    Attached Files:

  3. bigbird macrumors 6502

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    #4
    Nice pics, but use the correct terminology. The memory boards aren't called "PC boards". They're "risers". There is no left and right PC board, only upper (Riser A) and lower (Riser B) risers.
     
  4. Rt&Dzine macrumors 6502a

    Rt&Dzine

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    #5
    The MAC PRO MEMORY CONFIGURATIONS chart you've attached is very clear and easy to follow. It shows you exactly where to place the modules with every possible combination.
     
  5. Technoracle thread starter macrumors newbie

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    Dec 10, 2008
    #6
    While you are right about the correct Mac terminology (Risers), they (everything green with circuitry and hardware) are still generically known to old school guys like me as "Printed Circuit Boards". Nevertheless, I changed the terminology on my blog. I don't want to add more FUD into the world.

    Cheers!
     
  6. Technoracle thread starter macrumors newbie

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    Dec 10, 2008
    #7
    Anyone noticed a difference between 10-12GB and the full 16?

    I was thinking of going 16gb originally but everything I read seems to indicate that most apps cannot make use of more than 3-4GB. Since I produce Duane's World TV (http://www.duanesworldtv.com) and often run Final Cut Pro, Squeeze, Ableton Live 7 and Adobe After Effects which render at the same time, it made sense to go to 12. Not sure if any extra benefit would be felt with 16gb.

    Advice?

    Duane:confused:
     
  7. apple2E macrumors regular

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    #8
    I hear that the mac pros work best with matched sets and full top and bottom risers. I would recommend either 8gb 8X 1gb, or 16gb 8X2gb, or 32gb 8X4gb.

    I ran 6gb for a few weeks. I then moved to 10. Now I'm at 16. At 16 things are running really well. I use bridge, photoshop, illustrator, after effects, final cut pro, compressor and sorenson squeeze most of the time.
     
  8. rockinrocker macrumors 65816

    rockinrocker

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    Aug 21, 2006
    #9
    matching sets of 4 are supposed to be the best. something about a quad channel speed bump or something.

    barefeets has a write up...
     
  9. sickmacdoc macrumors 68020

    sickmacdoc

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    #10
    Well apple2E already responded, but I just wanted to add that the second OWC link he gave earlier shows the differences in performance graphically for virtually every memory configuration possible, so that is helpful here!

    http://eshop.macsales.com/Reviews/Framework.cfm?page=/Benchmarks/macproearly08ram/article.html
     
  10. Horst Guest

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    #11
    Ok, dumb question, Matching Sets , does that mean matching size or also requires the modules to be made by the same manufacturer/ have the same product # or such ?

    E.g., I have identical 2GB modules in the 1/2 slots of both rizer cards, but in the 3/4 slots I have 1GB pairs, each pair of a different make.
     
  11. sickmacdoc macrumors 68020

    sickmacdoc

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    #12
    FWIW, they specifically mention in the OWC installation video that it does means same manufacturer and model/type.
     
  12. Chaos123x macrumors 68000

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    Jul 8, 2008
    #13
    So wait wait....

    I gotta buy 4 more gigs of RAM?

    I have 4gbs now 1gbx4

    But I am getting 4 more gigs for X-mas 2gbx2.

    For 8gigs in total? or will only 6gigs show up?


    So I have to get another 2gbx2 to get it to work?

    I wanted to get 12gigs eventually but man this sucks I gotta spend another $100 or only 6gigs will show up?


    I'm confused still.

    :confused:
     
  13. sickmacdoc macrumors 68020

    sickmacdoc

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    #15
    Your 8Gb (4x1Gb +2x2Gb) should show up fine as 8Gb unless there is some unknown problem with your riser cards or RAM. The main thing you want to remember is that you want to install matching pairs of memory in pairs of slots-- in other words in your situation all four slots on Riser card A (upper) will be filled with something-- be it 4x1Gb sticks in slot 1,2,3 &4 or 2x1Gb in slots 1 and 2 and 2x2Gb in slots 3 and 4. The third pair of memory sticks (whatever is not used in the upper riser) will be installed in slots 1 & 2 of riser card B (lower).

    You just don't want to have sizes split across riser cards-- like a 2Gb in Riser A slot 1 and a 2Gb in Riser B slot 1 for instance.

    So probably for your use the simplest arrangement would be:
    Riser card A (Upper):
    Slot 1: 1Gb
    Slot 2: 1Gb
    Slot 3: 1Gb
    Slot 4: 1Gb
    Riser card B (Lower):
    Slot 1: 2Gb
    Slot 2: 2Gb
    which will result in 8Gb.

    If you were to get 2x2Gb later, they could go into riser card B slots 3 & 4 for a total of 12Gb with no problems (or any of about a dozen ways to arrange them!) ;)
     
  14. Rt&Dzine macrumors 6502a

    Rt&Dzine

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    #16
    No. You will have a total of 8 if you just add the 2x2. They are talking about "optimal" configuration. You definitely need pairs, but you don't need to have quads.

    Look at the Configuration Chart that Horst attached. You would put the new pair of 2gbs on Riser A, and your current 4x1gbs on Riser B for a total of 8.
     
  15. sickmacdoc macrumors 68020

    sickmacdoc

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    #17
    Yeah, that is interesting about that particular chart- because every other chart I have seen has shown that if you have three pairs (as in the case of the OP) then riser A should be full and riser B should only have slots 1 & 2 occupied! Go figure!
     
  16. bigbird macrumors 6502

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    #18
    I would suggest this RAM configuration:

    Riser A: 2 X 2GB in slots 1 & 2, 2 X 1 GB in slots 3 & 4
    Riser B: 2 X 1 GB in slots 1 & 2
     
  17. Horst Guest

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    #19
    I agree, that's a little odd; fwiw I found the chart here .

    Thanks for pointing me to the OWC installation video !
     
  18. Lumpydog macrumors 6502

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    #20
    Do not use this for Early 2008 Mac Pros

    Horst - the image in your post is and older image/instruction set - it does not hold true for "Early 2008" (current) Mac Pros.

    Apple switched up the two stick memory configuration. For example, the stock system comes with 2GB of memory - a 1GB stick on the top riser - and the second 1GB stick on the bottom riser. The posted image shows this incorrectly.

    Additionally, some other memory configurations shown on that chart are not correct for "early 2008" Mac Pros. The order that the risers and slots are filled with pairs is different now.

    Apple2E's first link is correct for early 2008 (8 core) mac pros.

    With more than two sticks, the memory is placed on each riser in matched pairs - in this order as you add matching pairs.

    Riser A (Top) slots 1 and 2
    Riser B (Bottom) slots 1 and 2
    Riser A (Top) slots 3 and 4
    Riser B (Bottom) slots 3 and 4

    Slots 1 in the one closest to the mother board and so on... You're best off putting the larger sticks in first (slots 1 and 2).

    The OP's blog shows the correct installation for his memory - the larger sticks in slots 1 and 2 on both risers.
     
  19. Rt&Dzine macrumors 6502a

    Rt&Dzine

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    #21
    So we need to know which version of the Mac Pro they have. Is there is a similar chart for the 2008 Mac Pro? (I'm jumping the gun and assuming the word "Early" won't be needed with 2008.) I've seen a few 2008 charts, but not with all the combinations.
     
  20. Horst Guest

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    #22
    Oups - sorry about that ....:eek:
     
  21. Lumpydog macrumors 6502

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    #23
    Not really your fault - Apple never provided a similar upgraded chart for the 2008 MPs - and they were quiet about the change.

    I've seen that chart in 2008 MP memory discussions - many times. Apple has really made this confusing - OWC has some nice guides to help us all out.
     
  22. Rt&Dzine macrumors 6502a

    Rt&Dzine

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    #24
    I was just looking at these test results at OWC that compare the 2.8GHz 4-Core with the 2.8GHz 8-Core.

    That is really interesting. I own a 2008 4-core single processor. Their tests show that the placement of the RAM doesn't effect how fast the data moves through in my machine like it does for the 8-core. Both machines suffer when you leave Riser B empty. But it looks like I don't have to be so concerned with matching upper and lower pairs.
     
  23. apple2E macrumors regular

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    #25
    Yeah it's crazy...and in my case also true! I started off with the original 2gb. I then added 4gb using two 2gb chips. The performance on rendering and such got a tad better. I then added another 4gb the same way for 10gb. This left my bottom riser empty 2 slots. There wasn't too much of a change. I went for it and filled both risers with 2gb chips for a total of 16. The performance is noticeable when i render hd video and during compression also. My geekbench scores went up alot also.
     

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