After Bootcamp - RAM is Hiding?

Discussion in 'Windows, Linux & Others on the Mac' started by uMac, Apr 19, 2008.

  1. uMac macrumors 6502

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    Canada
    #1
    I've installed XP Home on my Mac Pro and after the Install everything is running fine except the computer cannot see all the ram I have (I think it only sees the first chip)

    Suggestions?
     
  2. VoidBoi macrumors regular

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    Feb 5, 2007
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    Australia
    #2
    Depending how much RAM you have, XP Home may not be able to see all of it.
     
  3. uMac thread starter macrumors 6502

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    #3
    Well right now it only sees 2 GB, and my computer has like 9GB.
     
  4. Neil321 macrumors 68040

    Neil321

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    #4
    If its 32bit i think that's were the issue lies
     
  5. JNB macrumors 604

    JNB

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    #5
    I don't feel like rebooting right now to verify, but I believe that the max RAM in Windows (32-bit) was 2.196 GB
     
  6. uMac thread starter macrumors 6502

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    #6
    I've been reading that XP can take a maximum of 4GB, is that True?
     
  7. uMac thread starter macrumors 6502

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    #7
    2^32 = 4.29GB, so the max is 4GB
     
  8. weg macrumors 6502a

    weg

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    nj
    #8
    Theoretically, yes, but a large part of the 4GB is reserved for the operating system, so there are only 2GB available for the applications. He'll need the 64bit version of Windows XP or Vista 64.
     
  9. CanadaRAM macrumors G5

    CanadaRAM

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    #9
    32 bit Windows can theoretically address up to 4 GB BUT hardware addressing limitations mean that the total available to the OS is somewhere between 3.0 and 3.5 GB. On a PC, Windows itself will report 3 GB available (the space above 3 GB is used for drivers and resources), and the most available to a single application is 2 GB.

    Under Bootcamp, 32 bit Windows is restricted to 2 GB RAM regardless how much extra is in the Mac. This is an issue with the Mac's firmware/EFI. Scattered people have reported seeing 3 GB on MacBook Pros, but it is unclear whether this is an artifact of the Windows utility used to report the RAM size or not. (The addressable RAM is not affected by the /3GB and /PAE switches in Windows, as meny have posted without trying it -- these are for allocation of memory to applications within Windows.)
     
  10. JNB macrumors 604

    JNB

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    #10
    I was referring to a BC environment, I thought that was understood. Sorry for the confusion. CanadaRAM has the more detailed explanation.
     
  11. uMac thread starter macrumors 6502

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    #11
    Okay, thanks for the Info.
     
  12. fuzzielitlpanda macrumors 6502a

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    Mar 24, 2008
    #12
    32 bit versions of windows will see only up to 3gb of ram. if you plan on installing anything greater than that, run a 64 bit version.
     

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