Serious MP 2009 CPU question

Discussion in 'Mac Pro' started by Techhie, Oct 7, 2009.

  1. Techhie macrumors 65816


    Dec 7, 2008
    The hub of stupidity
    I currently have the stock 2.66 GHz base 2009 Mac Pro, and was looking at doing some upgrades. For all of you hardware vetrans out there, I had a few questions about processors:

    Can this board be installed on the quad model to replace the single-socket board?

    Can the new board be run as a single ship system until I can muster up the money for another CPU and heatsink?
    ^and would doing so allow me to take advantage of the extra RAM slots?

    Can the board be run with two chips at different clock speeds?

    Does the Octad setup require different processors than the quad allows (I know people have has success with Core i7, but I have heard horror stories involving fried logic boards and integrated heat spreaders)

    Is doing the upgrade cost effective? The site provides all of the materials required for the job and even extra processors.

    Any input would be appreciated :):D
  2. Macsonic macrumors 65816


    Sep 6, 2009
    Not sure if you've read this thread in the forum as Gugucom was able to upgrade the CPU of his 2009 Nehalem:

    What type of work do you use your MacPro for? If it's graphic design, in my opinion might not make much of a difference. I am not sure if the cost will be worth it with the added specs. Adobe softwares are still 32 bit and usually just use 1-2 cores. My boss also told me about Photoshop can only use a maximum of 4 gig of ram. This is only second hand information I am getting and I don't have supported proof of this. Maybe true because of the 32-bit issue.
  3. Dr.Pants macrumors 65816


    Jan 8, 2009
    Well, I am fairly certain that the dual-processor board can't run with only one processor. Doesn't mean it can, but there might be some problems since Apple actually designed two different daughterboards. Furthermore, running chips with two different clock speeds is not recommended, as it probably won't work and could potentially screw up the system.

    The above is AFAIK.

    However, when it comes to program's RAM usage, it really depends on how the program was written. 32-bit programs, for instance, can only address 4 GB of RAM nativity, but I'm sure they could be coded to use more, if needed. For instance, Leopard is a 32-bit OS but has some tricks with memory to address more then that.
  4. Tesselator macrumors 601


    Jan 9, 2008
    I think it can but finding someone who has actually done it is kinda crucial for confirmation.



    I read that it can but it surprised me to read so.

    Yes, different. But I think only if both processors are installed. I believe the SMT (dual capable) procs can operate in the single board and the single procs can operate in the dual board board if only one is installed. At least those are my guesses.

    Why ask that here? Go price hunting like the rest of us and subtract what you think you can get for the old left over components.

    That's all I got. :)
  5. J the Ninja macrumors 68000

    Jul 14, 2008
    Couple answers for you^
  6. gugucom macrumors 68020


    May 21, 2009
    Munich, Germany
    pretty sure it can

    I would expect you can. haven't tried it though.

    There is some lee way but Intel say any mismatch will increase errata. Ultimately you will have failures if speeds mismatch. Nobody knows the limits.

    Yep, dual CPUs Xeons are EXW55XX. Single CPU Xeons are EX35XX. It is an issue of memory management. The dual CPU chips have more QPIs.

    The problem with CPU replacement in Octads is

    1. the lack of clamps which causes you to crush the "pins" in the socket
    2. the reduced stroke (-1.8 mm) which prevents the fan and thermoelement connector to contact

    At list prices that is certainly a negative. I started with an Octad and got W5590s cheap as ES. That will not be possible in the future. It will take time for the 5580s and 5590s to come down in price. Gulftown may do it for you next year.
  7. Techhie thread starter macrumors 65816


    Dec 7, 2008
    The hub of stupidity
    Do you know if the hex-core chips will be drop in upgrades? I heard that they may run on slightly different voltages than the sockets on the current daughterboards provide.

    Also, Tesselator, you wouldn't happen to know anyone who has been in this situation before, would you? And could you provide a link to the information regarding differentiating CPU clocks in an octad?
  8. Umbongo macrumors 601


    Sep 14, 2006
    It seems very unlikely at this point.

    It is reference in one of the Intel offcial 5500 Xeon manuals. It's only a couple of line basically saying, it will work but is not supported or recommended. Try it by all means and report back, but I'd avoid it if you can.
  9. gugucom macrumors 68020


    May 21, 2009
    Munich, Germany
    Gulftown will be 32nm compared to 45nm in Gainestown. So this will definitely mean lower voltages on top of different microcode. The LGA1366 socket will stay though and it is expected that for Apple the 5520 chipset and logic board will carry on. Based on previous track record Apple will not make the MP5,1 or MP4,2 firmware available to MP4,1.

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