Faulty ram: replace the set, or just the one with errors?

Discussion in 'Mac Pro' started by digitalhen, Sep 24, 2011.

  1. digitalhen macrumors regular

    Jan 10, 2006
    Hi folks,

    I've got 3 sticks of 8GB ECC ram in my MP 2010. One stick is consistently generating a large amount of corrected errors per day, so I want to get it swapped before it gets worse. Confirmed this by moving it between slots - the errors follow.

    The maker has offered to swap either the individual stick or the whole set, for identical sticks in both cases. So, does an installed set need to be from the same batch, or will just the same model do? Given that the other two stick are fine, I was thinking of going for a single stick swap. :confused:

  2. nambuccaheadsau macrumors 68000


    Oct 19, 2007
    Nambucca Heads Australia
    If the supplier is going to replace e free of charge, ask for the whole lot.

    Normally just a need to replace the failing module is sufficient. Had a 2GB OWC module fail, identified the pair sand sent the two of to OWC and got to back free of charge.

    Of course depends how long it will take to mail back and forth and if you can be without you r Mac Pro.

    Same model is fine, running 8 x 2GB modules in my Mac Pro from three different manufacturers no problem. Mind you as a Mac Pro 2.1 they do have to be matched pairs.
  3. initialsBB macrumors 6502a

    Oct 18, 2010
    How did you test your RAM ? A 2010 MP I work with has 6 sticks of 8GB, and After Effects crashes way too often. Seeing as it's the only app we have that can fill the 48GB, I was wondering how I could nail it down to the RAM, and which stick.
  4. The-Pro macrumors 65816

    Dec 2, 2010
    Run memtest:

    or check your system profiler under the memory section for ECC errors. If they are really high with a certain stick (like 1 million) its most likely has problems. Also take out one stick at a time, run program, see if it crashes. If it does crash then that stick is probably not the problem. Then but the stick back in and take out the next one. And so on, until you find which stick is the problem, or several sticks.

    Mind you though that FormZ (3D rendering program) which I use crashes all the time on my 8 core 2009 MP which 12GB. Its a 32bit application, yes still :mad: , However it runs flawlessly on my 17" 2007 MBP with 4GB
  5. digitalhen thread starter macrumors regular

    Jan 10, 2006
    It's OWC where I bought the ram. They've been very responsive, but unfortunately can't do an advanced swap while I'm overseas... So I'll just swap out the one piece leaving me with a perfectly functional 16GB.

    So, I detected it in two ways - kernel.log in Console has detailed errors of timing and slot, and as mentioned, in System Profiler. I believe that the errors have been coming during a massive new Time Machine backup I did (2TB)... Perhaps while it does checksums? I've been getting 18 errors corrected every 24 hours. Apple apparently says the limit is 4 per 48 hours.

    I moved the the ram around to ensure that the failures followed the stick I suspected... It did.

    Hope that helps someone in the future
  6. initialsBB macrumors 6502a

    Oct 18, 2010
    Wirelessly posted (iPhone: Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_5 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8L1 Safari/6533.18.5)

    ECC errors show up in the memory tab under System Profiler ?

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