vista don't recongize 4 gigs of system memory

Discussion in 'Windows Vista Hardware' started by geo85706, Jul 9, 2006.

  1. geo85706

    geo85706 Guest

    Vista does not see the extra gig of memory, i have 4 1 gig ddr400 memory
    installed and the motherboard sees it but vista don't.
    geo85706, Jul 9, 2006
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  2. geo85706

    John Boy Guest

    You have to correct that in your BIOS. How to
    do it will be in your owner's manual. Vista
    sees all the RAM the BIOS lets it see.
    John Boy, Jul 9, 2006
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  3. geo85706

    Tom Scales Guest

    He said his BIOS DOES see it
    Tom Scales, Jul 9, 2006
  4. The BIOS will certainly see it but will usually keep some for its own
    purposes and not report it as available to Windows unless you find and
    change some settings which are often not available unless you have a
    motherboard aimed at overclockers.

    If available, change MTRR from its default of Continuous to Discrete.
    The Memory Hole setting can also affect the memory reported to Windows.
    Dominic Payer, Jul 9, 2006
  5. geo85706

    John Boy Guest

    On my Asus board in the BIOS there is "DRAM Over
    4G Remapping" that must be enabled for the OS to
    see most of the 4G. Even with it enable I still
    lose a little bit and don't see the full 4G.
    There is a memory "hole" by design. Enabling
    the 4G Remapping moves it around the "hole" so
    the OS can see it.
    John Boy, Jul 9, 2006
  6. geo85706

    Mick Guest

    I was just about to post a question on the forum is see if 32-bit vista had
    overcome this missing memory problem when I spotted this post.
    I have 4G memory and running xp pro , only 3G was available. Using xp pro
    64-bit I could see the full 4G of memory. It turns out that XP and ( VISTA
    32-bit as well?) both use address's out of the 4G memory range to address
    hardware devices. Each hardware device you have means less addressable RAM.
    So I guess the answer is yes, VISTA has the same problem.... looks like I am
    going to stay with 64-bit then.
    Mick, Jul 11, 2006
  7. geo85706

    Damion Guest

    From my understanding if you install 4 GIG of RAM it has to be below PC3200.
    I have an Asus K8V SLI NForce Deluxe and according to the manual if I can
    only install 2gig of DDR400, but anything below can be installed up 4gig
    which is the max. Consult you manual or Asus website on memory
    Damion, Jul 11, 2006
  8. geo85706

    Zapper Guest

    That must be an ASUS limit. I am running an MSI k8n-sliF with 4GB of DDR 400
    with no problems. I did have to enable the Discrete MTRR option and the H/W
    remapping of memory.
    I am runnign x64 with no x86 OS crashes when I try to use
    Media Center to watch Live TV though...not sure if it is related to the
    memory remapping(since the bios mentions this is only for 64 bit OS')
    Zapper, Jul 11, 2006
  9. geo85706

    Simon D Guest


    I am have the same problem missing 1 Gb of memory

    When I was running vista beta 2 32bit O/S, I could see all 4GB of memory,
    upgrade to RC1 Build 5600 I am now only seeing 3GB of memory.

    If I switch to vista RC1 64bit, I can see 4GB RAM on my system.

    No problem with my Bios, all set as suggested the problems is in this new
    build of vista RC1

    I still trying to find how can I address/access this missing 1GB when using
    32bit O/S?



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    Simon D, Sep 9, 2006
  10. geo85706

    billbrasky Guest

    Same deal here. My BIOS and Linux both see all 4GB of RAM, but Vista (x86)
    only sees 3GB of it. I'm also experiencing lots of BSODs with "MEMORY
    MANAGEMENT" errors. If I remove 2GB, everything works just fine...
    billbrasky, Sep 20, 2006
  11. geo85706

    billbrasky Guest

    Same deal here. My BIOS and Linux both see all 4GB of RAM, but Vista (x86)
    only sees 3GB of it. I'm also experiencing lots of BSODs with "MEMORY
    MANAGEMENT" errors. If I remove 2GB, everything works just fine...
    billbrasky, Sep 20, 2006
  12. geo85706

    jesusg Guest

    In my computer, Vista 5728 has stopped to see the full 4GB.

    My BIOS detects 4GB, and also SpeedFan, but Vista (now) only reports 2047 MB.
    jesusg, Oct 6, 2006
  13. geo85706

    Krax Guest

    Vista only recognizes up to 4Gb of ram... so have fun...
    Krax, Oct 6, 2006
  14. geo85706

    jesusg Guest

    2047 MB < 2 GB :)

    I know that 32 bits Vista can only address 4GB, but I want my 4 GB, not 2 GB.
    jesusg, Oct 6, 2006
  15. geo85706

    Rune Moberg Guest

    The problem is that PCI devices (such as graphics card...) map their memory
    into the system memory address space.

    You can see for yourself using Device Manager and look at View | Devices by
    type and then expand the Memory node.

    Since many device drivers are developed by brain-dead morons, MS wisely
    decided to limit their 32-bit desktop Operating Systems to a 32-bit address
    space. XP (and Vista) does support PAE, but only as a way to enable DEP. Use
    Windows 2003 Server or Windows "Longhorn" Server if you insist on using a
    32-bit OS.

    Incidentally, nVidia used to support PAE, but all forceware drivers after
    80.12 or so doesn't work correctly when faced with 64-bit addresses. (This
    might've been fixed in the latest driver revisions, I haven't tested this
    for a couple of months)

    Finally, if you have a 64-bit OS (or 32-bit Windows Server), you need to
    activate the memory hole feature so that the memory controller will remap
    one or more memory banks above the 4GB mark.

    Oh (sorry, when I said "finally" I lied), you should be aware that each
    32-bit process is limited to a 2GB address space. With a 64-bit OS, this
    grows to 4GB. So even if you're only running 32-bit processes, you will see
    some benefit from a 64-bit OS.
    Rune Moberg, Oct 8, 2006
  16. geo85706

    jesusg Guest

    Thanks, Rune

    My problem is not related to the ~3GB XP limit.

    I have seen the full 4GB, but during the software/hardware installation half
    the memory has gone. (I don´t know when it happened, but I'm sure it was in
    5728, and I don´t remember any action that could make this).

    From Device Manager, if I view Resources by type I can see the full address
    space to ffffffff, even some ranges in use by motherboard chipset, LAN
    adapters and graphics adapter, but there is an entry 80010000-ffffffff at the
    midle of the tree marked as 'PCI bus' that report a conflict (Memory Range
    80010000 - FFFFFFFF not available.). I think this is a Vista bug.

    I'll be happy to switch to x64 when some software makers develop 64bits
    drivers for their apps :)
    jesusg, Oct 28, 2006
  17. geo85706

    Evert Guest

    I have a similar case: 4GB of RAM on an ABIT AB9 Pro motherboard. BIOS sees
    4GB, WinXP Pro sees 4GB, but Vista RC2 sees 'only' 3326 MB...

    Evert, Nov 9, 2006
  18. geo85706

    Theo Guest

    You are seeing the affect of a "memory hole" as a result of
    the design of the motherboards that goes back to the days of
    the original ISA bus. It was presumed back then that we
    would never have enough memory in our computers to ever see
    this loss. Most BIOS have a setting to recover some of the
    lost memory, but usually not all of it. If I recall
    correctly EFI is supposed to do away with the "memory hole."
    Theo, Nov 9, 2006
  19. geo85706

    John Guest

    Same here. I'm using 4gb of 667mhz ram in my xps m1210. Vista Ultimate
    64bit Edition only see's 3326. Mobo verifies 4 though. This is a let down..
    John, Dec 9, 2006
  20. geo85706

    Rick Rogers Guest

    Hi John,

    It's because there is a 4GB limit on the available addresses. Some of these
    are reserved for the system's addresses, the remainder (what you see) is
    what is available for memory addressing. This is a limitation in the 32-bit
    system. You should not see this in the 64-bit version unless either a module
    is bad or the mainboard is not reporting correctly (or doesn't support it).

    Best of Luck,

    Rick Rogers, aka "Nutcase" - Microsoft MVP
    Windows help -
    Rick Rogers, Dec 9, 2006
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