I'm getting mad - sixth memory stick dead in Mac Pro 2008

Discussion in 'Mac Pro' started by Spacedust, Aug 23, 2012.

  1. Spacedust macrumors 6502a

    May 24, 2009
    Micron is making the most horrible memories I've ever seen. Out of 8 stick 6 are dead.

    So far other failed sticks were replaced with Micron (the same model), Kingston , Qimonda, Hynix, Nanya. Almost huge collection of different brands working together :) I think I'm only missing Elixir, FCM, GoodRAM and CSX :p

    Now I'm going to get cheap Qimonda sticks with large heatsinks (for the first time) and we will see how these will perform...
  2. G4DP macrumors 65816

    Mar 28, 2007
    This is the first time you've gotten ones with the correct Heat Sinks?
  3. paulrbeers macrumors 68040

    Dec 17, 2009
    Sooo you are now switching to the Apple recommended heat sinks and wonder why all the others died..... :rolleyes:
  4. goMac macrumors 603

    Apr 15, 2004
    Pretty sure this is why the heat sinks aren't a suggestion, they're a requirement...
  5. Neodym macrumors 68000


    Jul 5, 2002
    Not really. In my 1,1 I had two sticks with "slim" heatsinks and two with half big / half small heatsinks for several years. Despite the temperature being around 70-80 Centigrades on the slim ones I got not one single hiccup, even when running full load for several consecutive days (and nights)!
  6. Spacedust thread starter macrumors 6502a

    May 24, 2009
    If they can't work with small heatsinks then in 1U servers there should be fire ;)

    I've added some additional copper heatsinks on a core of a FB-DIMM chip, but this dropped temps only a little bit.

    It's time to start thinking about Mac Pro 2009 ;)
  7. thekev macrumors 604


    Aug 5, 2010
    Servers are often much noisier. Given that you weren't using something that was certified, there's no way to guarantee that it will work. It shouldn't have taken 6 sticks to figure that out. As for the 2009, they fixed refurb pricing. In the US hex core machines have come up around $2450. You should understand that things are cooled differently in a rackmount server.
  8. gpzjock macrumors 6502a

    May 4, 2009
    I replaced my Apple RAM with Memory America modules that have the full size heat sinks. In 4 years of running at 80 degrees 2 modules have gone bad out of 8. In each case the vendor has replaced all 4 sticks from the set containing the bad module with 2 matched pairs at postage cost only.
    Lifetime warranties FTW.
  9. ColdCase macrumors 68030

    Feb 10, 2008
    I dunno, but I purchased several sticks from DMS back in 2008 with big honking heat sinks and have never had an issue. In fact I don't think I've had a problem with their certified stuff since I started buying memory from them in the 90s.
  10. Snowshiro macrumors 6502

    Jan 12, 2008
    The only memory modules I've ever had die (3 in total) are the "official" Apple ones that came with the Pro. The ones I've bought from OWC have been rock solid. A bit sad really that Apple couldn't have done better with their choice of manufacturer.
  11. paulrbeers macrumors 68040

    Dec 17, 2009
    Umm, a server generally has large fans that push a lot of air thru them. The Mac Pros on the other hand are designed to sit next to a desk where noise from large fans are generally not tollerated. There's a big difference between servers and workstations. I know that seems crazy..... (or not)


    Also the 1,1 only uses 667mhz RAM and runs a lot cooler than the 800mhz Ram in the 3,1's. Also, it has been shown that for 512mb and 1GB sticks, the temperatures remain low enough that the slim heat sinks aren't as big of a deal but once you step up to 2GB and especially 4GB, they become even more necessary.
  12. Spacedust thread starter macrumors 6502a

    May 24, 2009
  13. Neodym macrumors 68000


    Jul 5, 2002
    Wow - 80 degrees with full-size heatsinks? I wonder what temperatures i could have achieved if i replaced that slims with the full-size heatsinks from my old 512MB modules...

    Not sure about that one. 800MHz is 20% more, granted - but i would expect the temperatures to only increase nonlinear, as the producers should have experience in fabrication after producing 667MHz for some time (thus better quality dies from the process) and therefore allowing for 800MHz in the first place. Depending on the module there might even have been a die-shrink somewhere along the way.

    With a linear increase we would be talking about 80 degrees plus 20%, thus getting close to 100°C, which i can't believe to be tolerated by neither the producer nor the purchaser, as the failure rate would probably skyrocket on such modules.

    Not according to my experiences: The slim heatsinks were sitting on the 4GB modules, whereas the 2GB modules had the half/half ones. And neither made any problems, despite the 78-80°C on the slim heatsink ones.
  14. jickerson macrumors newbie

    Aug 18, 2012
    Just curious (new to the "light" side of the force), but why are mac pro's so much more demanding on their RAM. I've built many a PC and always thought heatsinks on ram was just a gimmick, and never had any problems using non-heatsink sticks.
  15. paulrbeers macrumors 68040

    Dec 17, 2009
    Here's some good information on user experiences using the slim heat sinks vs apple recommended....



    You've probably never built a PC with FBDIMMS which is what the 1,1 - 3,1 Mac Pros use. The ABM chip on them get super hot and requires a lot of cooling. Regularly unbuffered, non-ecc RAM wouldn't have an ABM chip and therefore requires limited cooling.
  16. Neodym macrumors 68000


    Jul 5, 2002
    *Shrug* Did not read through that endless lines of text. Just wanted to contribute my personal experiences that seem to differ from the general consensus here. But as usual: YMMV!
  17. Spacedust thread starter macrumors 6502a

    May 24, 2009
    Just to let everyone now:

    4Rx8 sticks does not work in Mac Pro 2008 :/ I have to return them, but the good news is I've used some compressed air on my Micron stick and BOOM it's fully working again ! It was just a lot of dust under the heatsink.

    It passes all 8 tests in memtest with no errors...

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