MacPro 12 core RAM configuration

Discussion in 'Mac Pro' started by initialsBB, Dec 4, 2010.

  1. initialsBB macrumors 6502a

    Joined:
    Oct 18, 2010
    #1
    A company I am working for has decided to take the plunge on a 12 core MacPro for heavy duty After Effects work. I suggested getting Apple's 4x2 GB RAM configuration and buying 4 sticks of 8 GB modules bringing the total up to 40 GB. How would you guys suggest that the RAM modules be installed in the machine ? Is it best to put all the 8 GB modules on one riser and the 4 GB modules on the other ? Or spread out the sticks on the two risers ?

    From looking at the manual I can't figure it out and was somewhat confused by macsales.com stating that all modules had to be the same...
     
  2. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #2
    At least with OWC RAM, all modules have to be their 8GB ones so you can't mix e.g. the stock RAM with OWC 8GBs. I don't know is this the case with other manufacturers, maybe someone can confirm that.

    If you want 40GB with OWC RAM, then you need 5x8GB. Or even better, 6x8GB so both triplets will run in triple-channel (may help in AE)
     
  3. initialsBB, Dec 5, 2010
    Last edited: Dec 5, 2010

    initialsBB thread starter macrumors 6502a

    Joined:
    Oct 18, 2010
    #3
    Oh, damn :(

    If anyone has feedback on this issue I'd be thrilled. But I'll definitely call up my local RAM supplier for more info.
     
  4. johnnymg macrumors 65816

    johnnymg

    Joined:
    Nov 16, 2008
    #4
    As HH mentioned you'll get the best performance (triple channel) from a 6x mem configuration. If absolute performance is your goal, the question then falls to 6x 4GB or 6x 8GB.

    cheers
    JohnG
     
  5. Umbongo macrumors 601

    Umbongo

    Joined:
    Sep 14, 2006
    Location:
    England
    #5
    The reason you can't mix is because all the "Mac Pro" 8GB DIMMs are Registered memory, but all the other Mac Pro branded memory and that sold by Apple is unbuffered. Can't mix those types.

    There are only two 8GB UDIMM products out there to my knowledge. Both by Samsung. The only store I can find selling them is memory 4 less.

    http://www.memory4less.com/m4l_itemdetail.aspx?rid=fd_10&itemid=1459762188

    That should theoretically work in a Mac Pro with other UDIMMs. I doubt anyone has tested it yet though.
     
  6. Bithero macrumors newbie

    Joined:
    Nov 8, 2010
    #6
    RAM 8GB and 4GB mix

    I have a Quad MP 2010 and I guess the RAM configuration should be similar to the 12 core in terms of which modules can be mixed. The RAM speed is different - for the 12 core you should install 1333 MHz (10600) vs. 1066 MHZ
    (8500) in the Quad.
    I don´t know what OWC is selling, but I have 2 x 8 GB (IBM Server RAM with ECC) and 2 x 4GB Kingston (Value RAM with ECC) to give me a total of 24GB in my Quad. This configuration works without problems ! I put the 8GB modules in slot 1 and 2 and the 4GB modules in slot 3 and 4. After restart you get a system message if everything works correctly and you can of course check the details in the "about this mac" menue.
    My memory only runs with 1066 MHz speed although I put 1333 MHz modules.
    I guess this is due to the limitations of the Quad CPU and I hope my RAM will run faster as soon as I upgrade to a Hexcore CPU:)
    Hope this helps.
     
  7. initialsBB thread starter macrumors 6502a

    Joined:
    Oct 18, 2010
    #7
    @johnnymg you are of course absolutely right about installing RAM in triplets. However from all the benchmarks and comments I have seen on this issue state that the advantages of triple channelling are far outweighed versus having larger quantities of RAM, ie better for us to have 4x8 rather than 3x8 for example.

    @umbongo & @bithero thank you for the technical details... It all becomes much clearer now :)

    I'll see if I can't get them to stretch the budget for 6x8 GB and be done with it.
     
  8. JavaTheHut macrumors 6502

    JavaTheHut

    Joined:
    Aug 15, 2010
    #8
    I am running 4x8GB ECC Registered sticks in a 2.66@12core - 32GB OWC ram sticks works great easily handles multi tasking. I never tried to run the 2x2GB Apple sticks at the same time since they are incompatible with the 8GB sticks

    If you would like some benchmarks I can post?
     
  9. Uncle Pinny macrumors regular

    Uncle Pinny

    Joined:
    Jul 15, 2008
    Location:
    London
    #9
    2.66Ghz 12 Cores in our studio.

    We run ours with all banks full up - 26GB total (6x4GB Kingston and stock 2x1GB).
     
  10. Freida macrumors 65816

    Joined:
    Oct 22, 2010
    #10
    are you sure that i can't have 4x2 apple ram and 2x4 owc?

    As I've just received my owc ram and there is no way to return it :(
     
  11. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #11
    You can mix 2GB and 4GB modules but at least OWC's 8GB modules don't work with other modules. FYI, you have 4GB modules (2x4GB) so it should work
     
  12. Freida macrumors 65816

    Joined:
    Oct 22, 2010
    #12
    uff, what a relief. You got me worried here for a second.

    good to know its only 8gb sticks that won't work. Looking forward to my 16gb :) in total :)
     
  13. initialsBB, Dec 6, 2010
    Last edited: Dec 6, 2010

    initialsBB thread starter macrumors 6502a

    Joined:
    Oct 18, 2010
    #13
    Digging a bit more, and from this previous Macrumors forum thread
    http://forums.macrumors.com/showthread.php?t=995581
    it sounds like it's near impossible to find unregistered 8 GB RAM modules... so the choice is to mix 1/2/4 GB UNBUFFERED modules, or match 8/16 GB REGISTERED modules (in triplets for optimal performance, even though real world results won't benefit much if at all).

    Apparently unregistered 8 or 16 GB modules would cost 50% more to make, so manufacturers are either waiting or skipping it altogether. The above thread indicates that Samsung may make them, but you'd have to be able to find the exact reference in this Samsung PDF :
    http://www.samsung.com/global/busin.../dram/downloads/ddr3_product_guide_jul_10.pdf

    I now understand why Apple does not officially support the 8 GB and above modules... too complicated and un-Apple like.

    In my case, for After Effects HD comps using lights, cameras, motion blur & 3D layers, 8 x 4GB modules would be a bit short considering we are trying to cut down rendering time as much as possible. Local supplier has 6 x 8GB going for €1500 VAT exclusive so it's "only" €500 more than we were planning on spending on RAM anyways... All in all this is going to be one pricey baby, so I hope it lives up to expectations !!
     
  14. initialsBB thread starter macrumors 6502a

    Joined:
    Oct 18, 2010
    #14
    On a side note memory4less.com quotes the Samsung unbuffered 8GB module at $136.37 but buysamsungparts.com has the same thing for $751.18 ?!?!?!
     
  15. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #15
    Bit confused over the details...

    I take it you're using 4GB RDIMM sticks from Kingston (KVR1333D3D4R9S/4GI 4GB 1333MHz DDR3 ECC Reg CL9 DIMM DR x4 w/TS Intel ) with your 8GB RDIMM's from IBM (not seen 8GB UDIMM's from IBM; I even checked before posting, just in case they'd started doing so)?

    As per OWC, thier 4GB sticks are UDIMM only, and their 8GB sticks are RDIMM only (don't offer UDIMM in this capacity, though as Umbongo linked, they do exist from Samsung).
     
  16. Transporteur macrumors 68030

    Joined:
    Nov 30, 2008
    Location:
    UK
    #16
    I'm a little confused here as well. I always thought that it is impossible to mix UDIMM and RDIMM sticks in the Mac Pro. :confused:

    And does the Pro ship with UDIMM's or RDIMM's? I'm considering an upgrade myself (page in/out ratio is 4:1) and this stuff is really confusing!

    I thought about upgrading two Kingston 4GB sticks (KVR1333D3E9S/4G) to fill the two remaining slots, giving me a total of 20GB.
     
  17. Umbongo macrumors 601

    Umbongo

    Joined:
    Sep 14, 2006
    Location:
    England
    #17
    It is.

    UDIMMs. Apple only support 1333MHz ECC UDIMMs on 2010 Mac Pros, that is what all the memory they ship with is.
     
  18. initialsBB thread starter macrumors 6502a

    Joined:
    Oct 18, 2010
    #18
    Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_2_1 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148 Safari/6533.18.5)

    I found this on the Adobe forums, does anyone know how much of a performance hit we can expect with RDIMMs ?

    http://forums.adobe.com/thread/727170?tstart=0
    "The ECC Registered Dimms slow the ram performance down and are meant for server critical applications that are run 24/7 365 days a year."

    {Edit} I should google before shooting off :
    http://en.wikipedia.org/wiki/Registered_memory
    "the Intel "Westmere" 5600 series of processors {...} for two or more DIMMs per channel, RDIMMs will have lower latency and better bandwidth than UDIMMs."

    Reading into the Fujitsu White paper from the article's references, it becomes clear that in regards to Westmere Mac Pros, the ideal situation is 3 identical RDIMMs per processor. Having 6 RAM slots per processor would have been even better had Apple been a bit less stingy.
     
  19. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #19
    Umbongo's right; you cannot mix RDIMM and UDIMM together (Memory Configuration Tables in the Data Sheet do not have UDIMM + RDIMM configurations at all, and it gets detailed into rankings, .... ;deleted this from the post, but seems I should have left it in :eek:).

    But it is possible to mix 4GB and 8GB sticks of the same type, which is what I was trying to get at with the previous post, as there is both 4GB RDIMM and 8GB UDIMM in production.
     
  20. Transporteur macrumors 68030

    Joined:
    Nov 30, 2008
    Location:
    UK
    #20

    Great, thanks guys!
    Good to know that the Pro ships with UDIMM's, makes updates cheaper for those who want to keep their original RAM (about 80€ for a single 4GB stick, whereas 4GB RDIMM are about 110€). :D
     
  21. initialsBB thread starter macrumors 6502a

    Joined:
    Oct 18, 2010
    #21
    My local RAM supplier (Macway in France) got back to me stating that they could not yet tell me whether they sold UDIMMs or RDIMMS, although they added that they think the Mac Pros might not be compatible at all with RDIMMs !!?? This does not seem correct to me...
     
  22. Umbongo macrumors 601

    Umbongo

    Joined:
    Sep 14, 2006
    Location:
    England
    #22
    They will likely be doing what everyone else is. 1GB, 2GB and 4GB UDIMMs and 8GB RDIMMs. The memory is just rebranded, they aren't putting DRAM modules on PCBs or anything.
     
  23. Bithero macrumors newbie

    Joined:
    Nov 8, 2010
    #23
    Hi Nanofrog I checked my modules and made some pictures for you to check the exact type of memory. Actually I was not aware there are different 8GB sticks around, so maybe I was just lucky buying these ...:)
    I like the IBM/Samsung sticks, they are for blade servers and are very low profile with a heat shield. I just got two more and I am running now 32GB. Although I think the 24GB was enough for me I prefer to run the same type of sticks :eek:
    I believe the IBM list price for those sticks is around 750 Euros per piece, but I could not resist to buy them for less than half of that on eBay.
     

    Attached Files:

  24. Umbongo macrumors 601

    Umbongo

    Joined:
    Sep 14, 2006
    Location:
    England
    #24
    Yeah you have RDIMMs. Your IBM 8GB DIMMs are quad ranked which enables manufacturers to produce them cheaper, but lowers the speed when a channel is populated with more than one DIMM (the 4th DIMM in a Mac Pro) as you see with your 800MHz speeds.
     
  25. initialsBB thread starter macrumors 6502a

    Joined:
    Oct 18, 2010
    #25
    It's not with the 8GB modules you got lucky, but with the 4GB ones !
    You should look into replacing the 4GB modules with one 8GB module to step up to 1066MHz.
     

Share This Page