Mac Pro 5,1 - RAM Compatibility - Mixed

Discussion in 'Mac Pro' started by Vilhelm.83, Jun 30, 2017.

  1. Vilhelm.83 macrumors newbie

    Vilhelm.83

    Joined:
    Jun 30, 2017
    Location:
    Ottawa, Ontario
    #1
    I've got a 5,1 Mac Pro (2009 Firmware upgrade) which I've recently upgraded to a new CPU tray with 2 x 3.46 GHz 6-Core Intel Xeon. I've been successfully running 32GB (4x8GB) 1333 memory in it since I updated the firmware a few years ago. The memory has carried over on the upgrade and has continued to work fine. Now that I have 4 more slots, I thought it would be a good opportunity to ad another 32GB. I ordered another set of 4x8GB. After installing the the new DIMM's the Mac won't boot , and I get the blinking front light. I've removed the older DIMM's to test the machine with the just the 4 new DIMM's and it boots no problem. Tried removing one of the new DIMM's and replacing it with one of the older ones, and it doesn't boot.

    So, the Mac boots with the old RAM. The Mac boots with the new RAM. The Mac doesn't boot with a mix of the RAM.

    These are the original sticks I was using.

    Apple® — 974044A - 32GB (4x8GB) DDR3 ECC UDIMM PC3-10600 9-9-9-24 Apple ECC (974044A)

    And these are the new ones I just ordered.

    32GB (4X8GB) MEMORY PC3-10600 1333MHZ 1.5V ECC REG DDR3 240 PIN DIMM 2RX4

    The ones I just received seem to differ from the add. I actually received Kingston 8GB 2Rx4 PC3L - 10600R - 9-12-E2. Which appear to be a lower voltage (PC3L?) if I'm not mistaken. I'm not overly versed in memory so I'm not too sure if I should request a replacement or not. The add mentioned I may receive different manufactured sticks, but they would all meet the same specs. And Like I said, the machine boots with it, and does show ECC Enabled in the system profiler.

    Just wondering if I'm crazy, but these sticks should be compatible with each other, no? Is there anything else I can check, or test to see if I'm on the right path? Or could there be other issues I've created since upgrading my tray and CPU's?


     
  2. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #2
    No, the Apple ram is unbuffered and the Kingston RAM is registered. These two types of RAM can work independently but cannot be mixed in the same computer.

    I would return the Kingston RAM. 10600R ("R" for registered) is NOT the same spec as the advertised 10600. An exchange for equivalent unbuffered modules would be acceptable.
     
  3. Vilhelm.83 thread starter macrumors newbie

    Vilhelm.83

    Joined:
    Jun 30, 2017
    Location:
    Ottawa, Ontario
    #3
    Thanks. Looking through the ad's item specifics, it does mention registered. So it looks like I may be out of luck for a return. May have to do another order and eat the cost on that last batch.

    Forgive my ignorance, but as it stands now I can either order another set of Registered or Unbuffered to fill my machine. Is one preferred over the other? Doing a quick search on the subject was mostly out of my comprehension. This machine is primarily used for After Effects, Premiere, and Cinema 4D if that makes any difference.
     
  4. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #4
    Correct, you need to order another 4x8GB or RAM to make it 64GB in total.

    There is almost no restriction on mixing RAM in cMP as long as the spec is correct, EXCEPT, UDIMM cannot be mixed with RDIMM.

    You can mix ECC with no ECC. Mixing 1GB, 2GB, 4GB, 8GB, DIMMs all together. Mix 1066 with 1333, etc. But you cannot boot from UDIMM mix with RDIMM.
     
  5. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #5
    The ad states 30 day return policy. I would return it, eat the restocking fee instead of the whole amount, and buy unbuffered RAM to match your existing RAM.
     

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