Unusual Vista Memory issue (not usual limit issue) RRS feed

  • Question

  • I have a very strange issue with Windows Vista which no-one I have
    contacted can explain. I run Windows Vista Ultimate 32-bit on an ASUS
    A8N-VM motherboard. It did have 2GB of RAM in 4 x 512mb strips but I
    decided to max it out to 4Gb. This meant replacing all the modules. I
    know of the limitation in Windows where with 4GB installed only a little
    over 3GB is actually available. My system is fully patched with all available updates including SP1

    I have added (on recommendation by Crucial) 4 identical modules which
    are picked up with no problem by the BIOS. On boot up it recognises all
    4 GB and displays that it is running in Dual channel mode. Even Windows
    'sees' the 4GB as it says so in the Welcome screen and also at the
    bottom of the 'My Computer' window. When I look in 'System Information'
    it shows total physical memory is 2GB which means it is completely
    ignoring a whole 2GB.

    If I take one strip out it 'thus making a total of 3GB, the motherbord
    sees all 3 GB and so does windows. This time when I look in system
    information it tells me that there is  total physical memory of 2.5 Gb
    Why is there more available memory when there is 3GB than when there is 4GB?
    All the strips appear to be working independantly and the Vista memory diagnostics tool reports that there are no problem.


    Has anyone got any ideas?

    Sunday, January 25, 2009 8:25 PM

All replies

  • I have updated the BIOS and after optimising the settings I now get 2.75Total Physical memory. This is the case with 3GB installd and with 4 GB installed
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    Saturday, January 31, 2009 8:52 AM
  • That may be all that you're going to get - while the theoretical upper limit for addressable RAM in 32-bit Windows is ~3.25GB, the actual limit depends on your exact hardware configration.
    Namely, your videocard(s) are the biggest users of address space.

    Got details on your hardware setup, notably, your videocard(s)?

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    Monday, February 2, 2009 3:37 AM