ECC errors on new crucial memory

Discussion in 'Mac Pro' started by bonjavi, Feb 9, 2007.

  1. bonjavi macrumors member

    Mar 1, 2005

    I bought a couple of 2gb memory modules for my macpro and installed them, macosx and windows detected all memory (10gb, 4 modules of 2gb and 4 of 512mb) but when it started to warm, on reboot, I lose one of the memory modules, I mean, I have 2gb less of physical memory. So I checked the installation and everything was right, I changed the position on the slots of the 4 2gb modules with the one of the 4 512 modules that came with the computer and get 9 ECC errors on Macosx and 2 gb less on windows.

    So, until that point I was sure I would return my new modules, but then, I tried to install the new ones on the same position of each slot on each bay, so the new one was on dimm1 of A and the other new one was on 1 of B; both of them on the exterior slot, I mean so they get a bit more of air from the fan. So since that I didnt have any error on it; I tried the apple care test and with memtest (5 tests as recommended on its guide) and I didnt get any error, also I have been looking at the "about this mac" memory info and didnt had any ECC error. Only one time, working on windows x64 I lost 30mb , on the memory task physical memory info, but dont really know if that error is an error, I mean maybe windows is counting with some kind of cache or something, or maybe that error is coming from one of the old modules.

    So my question is what do you think? should I go on returning this modules? I didnt have any good experiences with returning things on internet and also dont really know if they're failing. Is this the correct way to install them, and because of it they were failing at the beginning? is just a matter of temperature and they will fail again on summer?

    Anyone had any similar experience or returns with crucial europe?

    Well thanks in advance,

  2. bartelby macrumors Core


    Jun 16, 2004
    Isn't Crucial RAM guaranteed?
    So you should have no problem in returning it.
  3. bonjavi thread starter macrumors member

    Mar 1, 2005
    Yes it is but I dont know if its ok like its now or if it will fail in the future.
  4. AlBDamned macrumors 68030


    Mar 14, 2005
    Send it back and get some more. Crucial are pretty good on this front from what I've read.

    If you have problems with the next lot then maybe it's time to worry about the Mac Pro, but chances are it's just bad RAM.
  5. TheFuzz macrumors regular

    Aug 18, 2006
    this happened to me yesterday. i left my machine rendering a 3d scene and when i got back all four modules i got from owc had ecc errors. it was a 51 hour render and the mem. temps never got below 160F. i emailed owc and am waiting to hear back from them. hopefully it's just this batch and not the brand i ordered. it appears that in my case i never lost access to the memory. i've attached a pic of the istat widget that shows all 6GBs available. are ecc errors normal with long renders where the machine is working at max for hours?

    Attached Files:

  6. bonjavi thread starter macrumors member

    Mar 1, 2005
    That was what I mean, that maybe its normal on long renders to have that kind of errors and it will be the same with the next couple they'll send me. I guess I will send them for a new ones but I'm not so sure that will change anything.
  7. TheFuzz macrumors regular

    Aug 18, 2006
    owc told me it was weird that all four would have the problem and set up an rma. he/she said they haven't had any problems w/ the brand so hopefully the next batch will be ok. we'll see.
  8. mjgunn macrumors member

    Sep 7, 2006
    How do you check for ECC errors, and how else can I test my ram (can you link to that memtest guide you mentioned?). I bought 2x1gb from Crucial on Monday, everything was working fine, and now I've had 2 kernel panics in 2 days. The chances are really good its the ram since before this I had only seen 1 panic since I got the machine in Sepetmber, but I would like to test them.
  9. dusanv macrumors 6502

    Mar 1, 2006
    Weird, but after two and a half months I am also just now seeing three ECC errors on one of the 512MB OWC modules.

    edit: they are labeled 'correctable errors'. Should I send them back?
  10. bonjavi thread starter macrumors member

    Mar 1, 2005
    You can check ECC errors from "about this mac" menu, and then more info, and on the memory tab.

    And about memtest here is some info:

    I didnt have any kernel panic since I installed the new ram, and have been doing some renders, not very long ones but... thats one of the reasons I were asking about keeping them or returning.
  11. CanadaRAM macrumors G5


    Oct 11, 2004
    On the Left Coast - Victoria BC Canada
    You have to distinguish between recoverable ECC errors, and unrecoverable ones. A certain, very low level of recoverable errors is exactly what ECC RAM is supposed to do - correct errors caused by cosmic radiation and random events.
    When the level rises though, it may be indicative of bad RAM (generating its own errors) heat, or a problem with the riser board itself or possible a corrupt OSX installation.

    Apple's standard, IIRC is four recoverable ECC errors over a 48 hour period.

    Obviously, if you are not using programs that utilize all of the RAM in the machine, then you won't be triggering as many errors. When you render though, you're stressing all of the RAM, typicall, and keeping it reading and writing continually for an extended time, so Final Cut is an excellent memory testing tool.

    How many recoverable ECC errors are you seeing, over what span of time?

  12. bonjavi thread starter macrumors member

    Mar 1, 2005
    I've only seen ECC errors one time, they were 9, and the computer have been rendering on windows for a couple of hours, then I noticed I had 2 gb less of memory and reboot to macosx, and when I checked the memory status one fo them had 9 ECC errors, dont know it they were recoverable or not didnt noticed that message.

    Since I changed the memory modules to the position I said in my first post, new one on the external place of each raiser, I havent seen errors again or memory loses on macosx. on windows on physical memory on task manager some times I see 30mb or 50mb less than when its started cold.

    What does that mean? should I change them?

    thanks again
  13. mjgunn macrumors member

    Sep 7, 2006
    Since i posted the other day, my system has been stable. I moved the 2 new crucial sticks up to the top riser slot, and the original 512s to the bottom, not sure if thats made the difference, or what.

    However, today I was working in windows, and I remembered other people mentioning windows reporting an incorrect amount of ram, so I went into properties, and windows was only showing 2gb of ram. When I got back into OS X, it was still reporting 3gb. Is this a windows issue, or something wrong with the ram?
  14. bonjavi thread starter macrumors member

    Mar 1, 2005
    You have to activate the 3gb switch if you're using a 32bits windows. look for 3gb switch on google
  15. D-rock macrumors member

    Aug 24, 2006
    City of Angels, Left Coast
    I'm pretty sure that has everything to do with the amount of memory a single app can access, NOT how much the system sees.

    XP and Win2k should be able to see 4GB of memory, IIRC.

    But it's late and my memory's a bit fuzzy.

  16. mjgunn macrumors member

    Sep 7, 2006
    Never knew that, I'll check it out next time I'm in windows, thanks.
  17. bonjavi thread starter macrumors member

    Mar 1, 2005
    Yeah I think so, but since he couldnt see the memory on windows its the only option I see that he could try. Im sure on OSX is the way you say but dont know on windows..
  18. synth3tik macrumors 68040


    Oct 11, 2006
    Minneapolis, MN
    Heh, we have the same names for our HDs.

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