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Usable memory question RRS feed

  • Question

  • Hi --

    If I run Windows 7 32-bit on a PC with 4 GB of RAM, how much of that 4 GB will Windows actually see?

    I'm trying to decide whether to install a 32-bit or 64-bit version of Windows 7 on a PC that can accommodate a maximum of 4 GB of RAM. On a 32-bit Windows XP box running 4 GB of RAM, Windows can't access about 700 MB of the RAM. I need to know if this is still the case with Windows 7.

    Thanks
    CL

    Sunday, March 25, 2012 5:25 PM

Answers

  • Yes, it is still the case: although 32 bits addressing can "see" up to 4 GB of RAM (2^32 = 4 G), 32 bit editions of Windows use at most 3 GB (sometimes even 3.5) and reserves the last one for internal purposes (for example, mapping the video card memory addresses, because the video RAM is shared with the PC's RAM).
    If you want to use all of the RAM installed in your PC, you have to install a 64 bit version of Windows.

    Bye.


    Luigi Bruno - Microsoft Community Contributor 2011 Award

    • Marked as answer by Chuck Lavin Monday, March 26, 2012 8:57 AM
    Sunday, March 25, 2012 5:41 PM

All replies

  • Yes, it is still the case: although 32 bits addressing can "see" up to 4 GB of RAM (2^32 = 4 G), 32 bit editions of Windows use at most 3 GB (sometimes even 3.5) and reserves the last one for internal purposes (for example, mapping the video card memory addresses, because the video RAM is shared with the PC's RAM).
    If you want to use all of the RAM installed in your PC, you have to install a 64 bit version of Windows.

    Bye.


    Luigi Bruno - Microsoft Community Contributor 2011 Award

    • Marked as answer by Chuck Lavin Monday, March 26, 2012 8:57 AM
    Sunday, March 25, 2012 5:41 PM
  • Thanks!
    Monday, March 26, 2012 8:57 AM