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  1. #1
    Super Moderator BATcher's Avatar
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    For this question, I'm assuming that a PC has 4 GB of real memory installed, and thus a motherboard which supports that at least that much real memory.

    It seems fairly well appreciated that a 32-bit operating system can address a maximum of 4 GB of virtual memory (e.g. see here), and for various reasons the amount that can be used by the operating system is just less than 3.5 GB.

    Some of the newer add-in graphics cards seem to have positively huge amounts of memory on them, perhaps as much as 1 GB.

    My question: Does the graphics memory usurp some of the ~3.5 GB of virtual memory address space, thus meaning (in the above circumstance) that Vista 32-bit would see only 3 - 1 = 2 GB?

    Thanks!
    BATcher

    Time prevents everything happening all at once...

  2. #2
    Plutonium Lounger
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    As far as I know, RAM, video and PCI devices all use addresses in the 4 GB (32-bit) address space, so video memory decreases the maximum available RAM.

  3. #3
    5 Star Lounger PaulB's Avatar
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    I can't find the reference now, but I do remember reading somewhere that dedicated video memory is addressed by the GPU (graphics processing unit) and not the CPU and is therefore not part of the 4 GB address space.

    But I have been known to be wrong at times.
    Regards,
    PaulB

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