Adding memory to 6GB (6x1GB) Mac Pro 2.26

Discussion in 'Mac Pro' started by xEradx, Apr 2, 2009.

  1. xEradx macrumors newbie

    Joined:
    Apr 2, 2009
    #1
    Someone bought me the new Two 2.26GHz Quad-Core Intel Xeon with 6GB (6x1GB) ram. I never upgrade memory through apple because of the price. But it would have been worth it to upgrade to 8GB (4x2GB) [Add $100.00]. But its too late now. My plan is to slowly get to 16GB (8x2GB) and the day that's not enough memory I will get a new MP. Never plan on putting 32GB in this Machine.

    So they say to install in pairs and on both cards. So you would need at least 4 sticks. What about in my case where I have only 2 free spots and it would not be worth it to buy 2 more 1GB stick and have no more room left. Can I get 2x2GB and add to my 6x1GB sticks? Or do I have to take out all my memory and get 4x2GB? That would seem like such a waste!
    I use the machine for Final Cut Studio 2.
     
  2. cmaier macrumors G3

    Joined:
    Jul 25, 2007
    Location:
    California
    #2
    yes, you can add 2GB sticks in the open slots.
     
  3. xEradx thread starter macrumors newbie

    Joined:
    Apr 2, 2009
    #3
    speeds?

    Will it make a speed difference to add the 2x2GB in the open slots? If there is, is it such a small diff that no one could really tell or would the difference not be as big as the gain of adding 4GB of memory???
    Does that make since?
     
  4. cmaier macrumors G3

    Joined:
    Jul 25, 2007
    Location:
    California
    #4
    It's impossible to answer this question without knowing how much memory your apps use on average. Adding sticks to the fourth slot reduces average bandwidth, but if you need more than 6GB for your software then the speed improvement caused by not having to swap to disk will more than make up for it.

    Personally, I'm planning on populating all four pairs of slots when my system arrives.
     
  5. galstaph macrumors 6502a

    galstaph

    Joined:
    Jul 24, 2002
    Location:
    The Great White North Eh
    #5
    keep in mind this machine has a sweet spot for triple channel memory configurations 6 (1x6), 12(2x6), 24(4x6). You get a higher bandwidth through the memory in triple channel than dual channel see barefeats
     
  6. cmaier macrumors G3

    Joined:
    Jul 25, 2007
    Location:
    California
    #6
    yes, but my point is if you actually need more memory than is physically available, you are much better off having it, even if the fourth slot has to drop to single channel; single channel is thousands of times faster than paging to disk.
     
  7. xEradx thread starter macrumors newbie

    Joined:
    Apr 2, 2009
    #7
    How are you populating all slots? 8x1GB? 6x1GB & 2x2GB or 8x2GB?
     
  8. cmaier macrumors G3

    Joined:
    Jul 25, 2007
    Location:
    California
    #8
    8x2GB to start. Once 4GB's drop in price quite a bit (a few years from now), I'll replace the 2's.
     
  9. xEradx thread starter macrumors newbie

    Joined:
    Apr 2, 2009
    #9
    Great Link! I understand now.
    But now even more bummed that I have the 1GB sticks! :( If I add 2x2GB it will help when using Motion, but slow things down for other apps that don't need 10GB. So I guess I will make the 6GB work until I can afford to get 6x2GB.
     
  10. cmaier macrumors G3

    Joined:
    Jul 25, 2007
    Location:
    California
    #10
    A lot of people misunderstand what the barefeats data shows. Even that page says:

    "If you have memory installed in all 8 slots of your 8-core Nehalem (or all 4 slots of a 4-core Nehalem), it may not penalize your real world application performance. The vast majority of real world applications do not saturate the memory bandwidth. Plus it's better to drop from triple channel to double channel performance than to run out of memory and start doing virtual memory disk swaps."

    Furthermore, even the test in barefeats is misunderstood. It shows two bars - in one, 6x2G, and in the other 8x2G, and it shows MB/s. In other words, it shows bandwidth. The average bandwidth goes down by 33%. But the test accessed 33% more RAM.

    The test doesn't show, at all, that you would have reduced performance in apps that only used 12GB. The grey bar test should have been limited to accessing the first 12GB to make that comparison, but it wasn't.
     
  11. Mac Husky macrumors regular

    Joined:
    Mar 28, 2009
    Location:
    Bavaria, Germany
    #11
    Lucky guy. I´m still looking for this "someone" :D

    Concerning your question: have a look at OWC data also.
     
  12. xEradx thread starter macrumors newbie

    Joined:
    Apr 2, 2009
    #12
    Yes I am very blessed. This is the second Mac given to me. The first was a 1.66ghz powerbook back in the power PC days. I gave it away march '08. Now someone give me a mac pro! Sweet!
    All I can say is be a blessing to people and it will come back around. ;)
     
  13. boogieman macrumors regular

    Joined:
    Nov 10, 2004
    #13
    So did I go wrong?? I done 6 sticks 2 gigs a piece.
     
  14. Mac Husky macrumors regular

    Joined:
    Mar 28, 2009
    Location:
    Bavaria, Germany
    #14
    Try to be on this very way for lifetime, BUT no 8-core "came back around" so far :D
     
  15. rikoshay macrumors member

    rikoshay

    Joined:
    Mar 28, 2006
    Location:
    No. California (in the Redwoods)
    #15
    As a point of reference, When I bought my 3.0 Ghz Mac Pro in late 2007, Apple was recommending that ALL 8 RAM slots were used for maximum speed & performance. I installed 12Gb (4 X 2Gb & 4 X 1Gb) in mine & it smokes. I keep the Activity Monitor going all of the time, & occasionally see a core pegged. Even using Safari! Whenever I use Studio Artist, I'll see all 8 cores using every bit of my RAM.
     
  16. Sun Baked macrumors G5

    Sun Baked

    Joined:
    May 19, 2002
    #16
    Use the 6GB, when the pageouts creep up, you can add more memory.

    Then you can decide how many Benjamins a half second is worth to swap apps faster, or when the pageouts creep up for the active app after a restart and it being the only app running.

    Remember on the pageouts, huge uptime, and opening 50 apps will distort the number and generally not affect the currently running app and only gives you a .5-2 sec slowdown while swapping an app into active memory.
     
  17. jons macrumors 6502

    Joined:
    Apr 24, 2008
    #17
    When you find him, let me know...
     
  18. xEradx thread starter macrumors newbie

    Joined:
    Apr 2, 2009
    #19
    no, thats great! Put 3 on 1 side and 3 on the other and you have triple channel memory. Thats what I want because 6gb is not enough for what I do but 12gb would be just right.
    Only add 2 more sticks if you need more memory, other wise leave it the way it is because it will be faster.
     
  19. xEradx thread starter macrumors newbie

    Joined:
    Apr 2, 2009
    #20
    what about dual channel? If you need to put them in pairs and equal on each side then could you put 2x1gb & 2x2gb on one side and the same on the other and it be dual channel? It would work like this on a PC.
    This would utilize the 1gb sticks I already have and be cheaper than buying 6x2gb.
     
  20. xEradx thread starter macrumors newbie

    Joined:
    Apr 2, 2009
    #21
    can anyone answer the question i quoted?
     
  21. jjrecort macrumors newbie

    Joined:
    Jun 15, 2009
    #22
    Hello to all,

    I just have bougth a 2.26..
    I basically do FCP, Motion and Shake.

    I have been reading this thread and my question is.

    What is best

    A; 6x1GB + 2x 2GB
    B; 4x1GB + 2x 2GB (sacrifice 2GB to keep the 3 channels)

    I'm planning to have a full 6x2GB.. but little by little (better said project by project)

    Any feedback?
    thanks...
     
  22. Spanky Deluxe macrumors 601

    Spanky Deluxe

    Joined:
    Mar 17, 2005
    Location:
    London, UK
    #23
    Both those modes would lose you triple channel mode so between those two, take the first with more RAM.

    Ideally though, you'd want 6x2GB.
     
  23. jjrecort macrumors newbie

    Joined:
    Jun 15, 2009
    #24
    So, if I mix memory sizes even having 3 Memory modules for each Processor I'm still loosing the 3 channels.

    So to have the 3 channels all six modules MUST be the same size. rigth?

    Well, my aim is to have 6x2GB..obviously... but I will be buying it little by little.. this way I'm not adding 720 EUR at once..

    thanks!
     
  24. Spanky Deluxe macrumors 601

    Spanky Deluxe

    Joined:
    Mar 17, 2005
    Location:
    London, UK
    #25
    Triple channel needs to have identical memory chips to work. However, what *might* work is 3x1GB and 3x2GB although someone more knowledgeable might know for sure.

    Alas, this is too late for you now but I think the most cost effective way of getting 12GB from the get-go is to CTO the machine from Apple with 4x2GB and then getting 2x2GB after market.
     

Share This Page