Bootcamp 1.4 XP Pro-Only 3GB?

Discussion in 'iMac' started by wcalderini, Aug 20, 2007.

  1. macrumors member

    Joined:
    Dec 7, 2004
    #1
    The basics.
    New SR AL iMac 20 inch ($1499 Model).
    Installed 2x2GB Ram chips. All looks fine in OSX, 4GB recognized.
    Bootcamp 1.4, Fresh Windows XP Pro installed, under "system" control panel tab it is only showing "2.98 GB" memory installed.
    I could understand it if only 2GB appeared as it may not be seeing one of the chips, but 2.98? That does not make a whole lot of sense.
    Just wondering if there was some "Windows" memory limit on this chipset under XP that I had not read about.
    Would upgrading to Vista make a difference?
    Have I done something noobish and not realized it?
    Any similar experiences out there?

    BC
     
  2. macrumors 6502a

    Joined:
    Nov 6, 2006
    #2
    XP cannot use more than 3GB. Upgrading to Vista will do it for you.
     
  3. thread starter macrumors member

    Joined:
    Dec 7, 2004
    #3
    That will do it then.
    Thanks a bunch.
    Never knew that.
    And was actually looking for a good enough excuse to plunk down the $99 for the upgrade anyway.

    BC
     
  4. TBi
    macrumors 68030

    TBi

    Joined:
    Jul 26, 2005
    Location:
    Ireland
    #4
    At least post accurate information...

    Vista 32-bit has the same limitation as XP 32-bit.

    However, BOTH XP 64-bit and Vista 64-bit can see more than 3 GB.

    So vista won't solve your problem unless you get the 64bit version.

    EDIT: This is a limit of the 32-bit memory address space. You don't have this problem in OSX because it's running in 64bit.
     
  5. macrumors 68000

    wakerider017

    Joined:
    Sep 20, 2006
    Location:
    US of A
    #5
    Woah, I thought Tiger was 32bit...


    They are making a big deal out of leopard being 64bit.


    "Leopard delivers 64-bit power in one, universal OS. Now the Cocoa application frameworks, as well as graphics, scripting, and the UNIX foundations of the Mac, are all 64-bit. And since you get full performance and compatibility for your 32-bit applications and drivers, you don’t need to update everything on your system just to run a single 64-bit application."
     
  6. macrumors 6502a

    Joined:
    Nov 10, 2006
    #6
    Tiger is partially 64-bit. It can use more than 4GB memory and command line apps can be 64-bit but not GUI apps. In Leopard everything is 64-bit even gui apps.
     
  7. TBi
    macrumors 68030

    TBi

    Joined:
    Jul 26, 2005
    Location:
    Ireland
  8. macrumors 6502a

    Joined:
    Nov 6, 2006
    #8
    Oh yeah, you are right. Sorry about that.
     
  9. macrumors 68000

    wakerider017

    Joined:
    Sep 20, 2006
    Location:
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    #9
    Okay thanks, didn't know that. :)
     
  10. macrumors 6502

    Joined:
    Jul 5, 2005
    #10
    That all makes sense - but why can GUI apps like PS access more than 3GB in Tiger?
     
  11. macrumors 6502a

    Joined:
    Nov 8, 2006
    Location:
    Baltimore
    #11
    Because darwin supports it.

    Leopard being 64-bit across the board means that GUI apps will be compiled to take advantage of 64-bit math. "64-bit" isn't some kind of magic that lets you use lots of RAM :]

    Most apps won't run noticeably different compiled for 64-bit CPUs, and some will actually run slightly slower depending on the compiler (32-bit calculations are faster, of course, and if your compiler decides to use a 64-bit operation when it wasn't needed...)
     
  12. TBi
    macrumors 68030

    TBi

    Joined:
    Jul 26, 2005
    Location:
    Ireland
    #12
    Intel chips will run faster in 64-bit mode due to increased register count. G5 chips will be the same or slower.
     

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