MacPro 08 memory upgrade, fine in OSX not recognised in XP

Discussion in 'Mac Pro' started by Trivial rock, Apr 16, 2009.

  1. Trivial rock macrumors regular

    Trivial rock

    Joined:
    Oct 9, 2008
    #1
    I installed an extra 4GB of crucial memory into my 08 MP and works fine in OSX however only the original 2GB is recognised in XP not the full 6GB any ideas?

    All help is much appreciated.
    Thanks in advance.
     
  2. ayeying macrumors 601

    ayeying

    Joined:
    Dec 5, 2007
    Location:
    Yay Area, CA
    #2
    XP Professional is a 32-bit system. It will only read upto 2GB on the Mac Pro. ~3.3GB on the other systems.
     
  3. macuserx86 macrumors 6502a

    macuserx86

    Joined:
    Jun 12, 2006
    #3
    It should be able to address the a little over 3 GB with the Mac Pro too. I have 32 bit Vista Premium Super Ultra Ichiban (**** Microsoft's naming scheme) and it could only see 2GB, then I upgraded to SP 2 and it now registers 4GB.
     
  4. Trivial rock thread starter macrumors regular

    Trivial rock

    Joined:
    Oct 9, 2008
    #4
    Thanks for the help guys, a little disappointing but Im about ready to purchase a new Windows OS for casual gaming and a few bits of software. I shall wait for windows 7.
     
  5. jbrenn macrumors 6502a

    Joined:
    Aug 27, 2008
    #5
    Microsoft made a change in the way vista recognizes ram with sp1 it now shows what is installed not what is usable it will only use about 2.00 gb ram.
    it addresses 4gb then subtracts out memory for the video ram and other things what is left over is the system ram. I have a macbook pro and in windows it registers 2.72.
     
  6. ayeying macrumors 601

    ayeying

    Joined:
    Dec 5, 2007
    Location:
    Yay Area, CA
    #6
    Vista will tell you, you have 4GB, but you're only using 2GB if you add up the numbers in Activity Monitor.

    Its a problem with the EFI -> BIOS conversion in the Mac Pro that only allows 2GB for some reason. It should really address upto 3GB but it doesn't.

    Its not a Windows fault, its 32-bit. You need 64-bit to address all the ram available.
     
  7. jbrenn macrumors 6502a

    Joined:
    Aug 27, 2008
    #7
    Make sure you get a 64 bit os. Since you have the ram you might as well be able to use it.
     
  8. Trivial rock thread starter macrumors regular

    Trivial rock

    Joined:
    Oct 9, 2008
    #8
    Yea it shall definitely be a 64bit OS, I would be surprised if windows 7 came out with a 32bit version but I guess we shall see.

    Thanks for the clarification guys.
     
  9. macuserx86 macrumors 6502a

    macuserx86

    Joined:
    Jun 12, 2006
    #9
    Interesting, I wasn't aware of that. That would explain why Crysis takes so long to load ;)
     
  10. kevink2 macrumors 65816

    Joined:
    Nov 2, 2008
    #10
    Will still be 32 bit version. Atom chips are still 32 bit, and 7 is supposed to support netbooks.

    If apple wanted to better support other os's they would allow at least 3gb of ram to be visible:)

    At least they provide bootcamp for dualbooting.
     

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