Huh, my 2x4GB DIMMs showing up as 2x2GB - I had 18GB now only 14GB RAM!

Discussion in 'Mac Pro' started by MythicFrost, Oct 6, 2009.

  1. MythicFrost macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #1
    I installed SL on my hard drive (upgrade from Leopard) and it worked great, just popped in my Intel X25-M G2 160GB today, installed SL.

    I checked my About This Mac info and it shows I have ONLY 14GB RAM, I had 18GB before...

    Does anyone know why?

    I also just noticed that in the Serial ATA Device Tree, the Intel ESB2 AHCI has just replaced the text for the normal owner of a partition...
    IE I have a hard drive setup as one partition (Macintosh HD) and the name of that physical drive that shows up would be like uhh ... something something, and it's now all Intel ESb2 AHCI, all of em, it doesn't appear to matter, just curious

    Kind Regards
     
  2. UltraNEO* macrumors 601

    UltraNEO*

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    Jun 16, 2007
    Location:
    近畿日本
    #2
    Maybe one or more otf the modules have come loose? Dust? or simply because the Mac prefer them to be in a different order... Try shuffling them.
     
  3. 300D macrumors 65816

    300D

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    Tulsa
    #3
    Click "More Info..." and see which ones are missing.
     
  4. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #4
    It was working such a short time ago, literally a week ago I had leopard and it showed 18GB. I did just install the SSD but I don't think that would cause or even cause dust to interfere with the RAM.

    I have 8 slots, 6x2GB, 1x2GB, I had 4x2GB and 2x1GB and 2x4GB.
    I'm really confused...

    EDIT: 6x2GB 2x1GB* not 1x2GB

    I don't really want to shuffle them, but I will if I have to...

    My dad also added 8GB that we bought months ago to his machine, in the identical order to mine, it shows 18GB he is on 10.5.8.

    Kind Regards
     
  5. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
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    Australia
    #5
    NOTE: just found this!

    Power On Self-Test:

    Last Run: 7/10/09 3:23 PM
    Result: Failed
    Failure Type: Memory
    Memory Slot: DIMM 3/DIMM Riser B

    under Diagnostics in System Profiler... What does that mean? lol - I have an idea...

    I think RAM likes to be in groups of two, so if DIMM 3 has failed, maybe DIM 4 reduced to 2GB with it?

    Kind Regards
     
  6. electroshock macrumors 6502a

    electroshock

    Joined:
    Sep 7, 2009
    #6
    Well, if you both have similar Mac Pros, why not -- just as a quick test -- swap the boot drive in both machines, then boot. Check Profiler to see how much memory each sees.

    If it's truly a hardware issue, the report will be same on each machine even if you've swapped the boot drives.

    So if, after swapping drives, your MP still reports 14 MB, start thinking about replacing the RAM in the bank that reported a hw mem test failure.
     
  7. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #7
    I can't, he is busy and will be for a while.

    I booted into Snow Leopard on my hard drive, it also showed 14GB,
    I can try booting into Windows 7 too? would that help?

    It's weird because it didn't disappear, it just dropped from 4GB to 2GB???

    I really don't want to have to get a new one, I bought it from OWC it should be under warranty...

    Kind Regards
     
  8. alecgold macrumors 6502a

    alecgold

    Joined:
    Oct 11, 2007
    Location:
    NLD
    #8
    IMHO and experience faulty memory can play with you like nothing else. I've had memory that worked, didn't work, worked for a week, then got faulty again, got half the memory. Man that made me mad :)

    But this looks to me like a clear case of failing memory.

     
  9. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #9
    Would I be able to pull out DIMM 3 / DIMM Riser B without pulling out DIMM 4 / DIMM Riser B?

    It means I'd have only 7 RAM modules, 4x2GB, 2x1GB, 1x4GB.. is that possible?

    Kind Regards
     
  10. ungraphic macrumors 6502a

    ungraphic

    Joined:
    Nov 15, 2007
    Location:
    Toronto, Canada
    #10
    I had a similar problem with RAM i purchased made by Kingston, for my first generation Mac Pro. I bought 2x2gb sticks. I already had 4x512mb, so I would have had a total of 6gb. I installed the ram and it came out at 4gb total. I repositioned the ram and restarted the mac, and got my full 6gb.

    After about 2 weeks, after doing some random fiddling around with settings and such, I checked my mac pro's system specs (just to drool at its awesomeness) and noticed my RAM went down from 6gb to 4gb. I checked everything; repositioning of ram, swapping ram out (isolated old ram, isolated new ram), ram tests, pram resets, etc. What I found that the kingston modules were showing up as 2x1gb. So i tried running them on their own (only one module in the mac). Sure enough, a red light flashed on the riser card and one of them had dropped down to 1gb of available memory, the other was fine. When paired, I got a total of 2gb. I got it quickly replaced for new working ram. I'm still a little skeptical of kingston, eventhough its brand name. Hopefully the new modules I got will last me a good while.

    Here's my thread if you wanna read more into it;

    http://forums.macrumors.com/showthread.php?t=791432
     
  11. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #11
    Thanks, was it only one module that was the problem? if you removed the faulty module did the other module still work?

    Kind Regards
     
  12. ungraphic macrumors 6502a

    ungraphic

    Joined:
    Nov 15, 2007
    Location:
    Toronto, Canada
    #12
    Yes, using only one module (of the two) worked fine. However, one of them was showing as 1gb. Both worked, except one was showing up as 1gb and the other as 2gb, so obviously one failed. When they got paired up in the system, they both registered as 1gb each. It could be just one module that failed on you.

    Try seeing which one it is, and then call up the place you bought them from and have them exchange it. If your past the '30 day refund/exchange policy' youll probably have to take it up with the manufacturers regular '1 year warranty' And if your past the year mark, well......looks like your SOL. Unless your warranty is longer.

    Hope this helps.
     
  13. MythicFrost thread starter macrumors 68040

    MythicFrost

    Joined:
    Mar 11, 2009
    Location:
    Australia
    #13
    Alright, thanks.. I'll pop that DIMM out and send it back to OWC.
    Apparently they have a lifetime replacement warranty.

    Kind Regards
     

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