Vista 32bit does not recognise 4GB memory

Discussion in 'Windows Vista Installation' started by GreatGuruMemsahib, Mar 3, 2007.

  1. I am having a problem with Windows Vista 32bit. I have installed 4GB Kingston
    667 memory on an ASUS P5B Deluxe motherboard. Vista only recognises 3GB of
    the memory. I understand that certain devies require memory mapped access. I
    have a 256MB video card that will take up sojme of the available address
    space. I also understand that 32bit versions of Vista limit the total
    available memory to 3.12GB.

    I have attempted to enable the memory remapping feature in the BIOS setup.
    When I return to Vista, it only recognizes 2GB of memory.

    Is there any way around this problem other than installing the 64bit version
    of Vista?

    In addition, if installing the 64bit version of Vista, will all of my
    applications run successfully? I do have a few custom business apps running
    and I do not know whether they have drivers for 64bit operation.

    Thanks I realize that all of this is quite complex, but I am curious as to
    whether there are any answers out there.
     
    GreatGuruMemsahib, Mar 3, 2007
    #1
    1. Advertisements

  2. GreatGuruMemsahib

    rogelah Guest

     
    rogelah, Mar 3, 2007
    #2
    1. Advertisements

  3. GreatGuruMemsahib

    rogelah Guest

    It is not a problem. You can look in your BIOS and see if you have 4GB. The
    operating system has to have some space allocated for it to do its work; it
    needs buffers for I/O and needs to have memory to allocate for the data
    structures it needs to keep track of things. The 3.12GB is the amount of
    space that can be allocated for your Working Set. Actually, your working set
    in memory at any one time may be less. There may also be other programs in
    memory at the same time; such as your mail agent that periodically checks for
    mail. Ideally, the operating system tries to keep in memory what it may need
    next. If it doesn't have it in memory then it has to fetched from virtual
    memory. That may mean that other parts of your working set that are not
    likely to be needed are overlaid by the code bing fetched.

    I don't think you need to go to 64-bit just because 64-bit can address 2^64
    locations. If you have only 4GB of memory and a 64-bit operating system there
    will still be the same allocation for the operating system. If you add memory
    over 4GB then you will need a 64-bit operating system to access the memory
    above 2^32 locations.
     
    rogelah, Mar 3, 2007
    #3
  4. Hello,
    Sorry but no. The hardware in the system is reserving the address space.
    Since 32-bit processors are limited to 4 gig of address space, hardware
    that requries addressing( like video cards or other devices including PCI)
    has to reserve some of the address space, thus limiting the amount of RAM
    that is available to Windows. Windows is not reserving that memory, the
    hardware in the system is reserving that space. Since there is a
    limitation of 4 gig of address space and there is overlap, the amount of
    RAM that can be addressed is reduced by the amount of address space the
    hardware requests.
    Thanks,
    Darrell Gorter[MSFT]

    This posting is provided "AS IS" with no warranties, and confers no rights
    --------------------
    |>Thread-Topic: Vista 32bit does not recognise 4GB memory
    |>thread-index: Acdd5zio4a06f0dITDOOQxEcwejddQ==
    |>X-WBNR-Posting-Host: 67.35.76.243
    |>From: =?Utf-8?B?cm9nZWxhaA==?= <>
    |>References: <>
    |>Subject: RE: Vista 32bit does not recognise 4GB memory
    |>Date: Sat, 3 Mar 2007 14:56:47 -0800
    |>Lines: 41
    |>Message-ID: <>
    |>MIME-Version: 1.0
    |>Content-Type: text/plain;
    |> charset="Utf-8"
    |>Content-Transfer-Encoding: 7bit
    |>X-Newsreader: Microsoft CDO for Windows 2000
    |>Content-Class: urn:content-classes:message
    |>Importance: normal
    |>Priority: normal
    |>X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.2757
    |>Newsgroups: microsoft.public.windows.vista.installation_setup
    |>Path: TK2MSFTNGHUB02.phx.gbl
    |>Xref: TK2MSFTNGHUB02.phx.gbl
    microsoft.public.windows.vista.installation_setup:11232
    |>NNTP-Posting-Host: TK2MSFTSBFM01 10.40.244.148
    |>X-Tomcat-NG: microsoft.public.windows.vista.installation_setup
    |>
    |>
    |>
    |>"GreatGuruMemsahib" wrote:
    |>
    |>> I am having a problem with Windows Vista 32bit. I have installed 4GB
    Kingston
    |>> 667 memory on an ASUS P5B Deluxe motherboard. Vista only recognises 3GB
    of
    |>> the memory. I understand that certain devies require memory mapped
    access. I
    |>> have a 256MB video card that will take up sojme of the available
    address
    |>> space. I also understand that 32bit versions of Vista limit the total
    |>> available memory to 3.12GB.
    |>>
    |>> I have attempted to enable the memory remapping feature in the BIOS
    setup.
    |>> When I return to Vista, it only recognizes 2GB of memory.
    |>>
    |>> Is there any way around this problem other than installing the 64bit
    version
    |>> of Vista?
    |>>
    |>> In addition, if installing the 64bit version of Vista, will all of my
    |>> applications run successfully? I do have a few custom business apps
    running
    |>> and I do not know whether they have drivers for 64bit operation.
    |>>
    |>> Thanks I realize that all of this is quite complex, but I am curious as
    to
    |>> whether there are any answers out there.
    |>
    |>It is not a problem. You can look in your BIOS and see if you have 4GB.
    The
    |>operating system has to have some space allocated for it to do its work;
    it
    |>needs buffers for I/O and needs to have memory to allocate for the data
    |>structures it needs to keep track of things. The 3.12GB is the amount of
    |>space that can be allocated for your Working Set. Actually, your working
    set
    |>in memory at any one time may be less. There may also be other programs
    in
    |>memory at the same time; such as your mail agent that periodically checks
    for
    |>mail. Ideally, the operating system tries to keep in memory what it may
    need
    |>next. If it doesn't have it in memory then it has to fetched from virtual
    |>memory. That may mean that other parts of your working set that are not
    |>likely to be needed are overlaid by the code bing fetched.
    |>
    |>I don't think you need to go to 64-bit just because 64-bit can address
    2^64
    |>locations. If you have only 4GB of memory and a 64-bit operating system
    there
    |>will still be the same allocation for the operating system. If you add
    memory
    |>over 4GB then you will need a 64-bit operating system to access the
    memory
    |>above 2^32 locations.
    |>
     
    Darrell Gorter[MSFT], Mar 5, 2007
    #4
  5. GreatGuruMemsahib

    Joe Guidera Guest

    Agreed, however shouldn't enabling memory re-mapping (which if I recall maps
    the address space above the 16GB line which properly allows hardware devices
    to map within the first 4GB of address space) solve the issue? Or does
    Vista not handle this? I know server does, but does Vista?

    Joe

     
    Joe Guidera, Mar 5, 2007
    #5
  6. Hello Joe,
    The firmware has to support the re-mapping. (workstation and server
    machines usually do)
    The processor has to support the remapping( most current processors should).
    You need to be running with PAE enabled
    Now the hardware can be remapped above the 4 gig addess space. However not
    all drivers work well after being remapped so other issues can occur.

    Thanks,
    Darrell Gorter[MSFT]

    This posting is provided "AS IS" with no warranties, and confers no rights
    --------------------
    |>From: "Joe Guidera" <>
    |>References: <>
    <>
    <oRer1#>
    |>Subject: Re: Vista 32bit does not recognise 4GB memory
    |>Date: Sun, 4 Mar 2007 20:23:58 -0600
    |>Keywords: < Not Specified >
    |>Lines: 114
    |>Message-ID: <>
    |>MIME-Version: 1.0
    |>Content-Type: text/plain;
    |> format=flowed;
    |> charset="iso-8859-1";
    |> reply-type=original
    |>Content-Transfer-Encoding: 7bit
    |>X-Priority: 3
    |>X-MSMail-Priority: Normal
    |>X-Newsreader: Microsoft Windows Live Mail desktop 8.0.1226
    |>X-MimeOLE: Produced By Microsoft MimeOLE V8.0.1226
    |>X-MS-CommunityGroup-PostID: {C224663C-8DFD-4410-AC72-EA4A9B5787C2}
    |>X-MS-CommunityGroup-ThreadID: 2C05B223-D3FB-4A82-972C-B988745EC2E7
    |>X-MS-CommunityGroup-ParentID: FD7006D9-D2B7-407C-A8CC-79B439BD9E42
    |>Newsgroups: microsoft.public.windows.vista.installation_setup
    |>Path: TK2MSFTNGHUB02.phx.gbl
    |>Xref: TK2MSFTNGHUB02.phx.gbl
    microsoft.public.windows.vista.installation_setup:11417
    |>NNTP-Posting-Host: TK2MSFTNGHUB02.phx.gbl 127.0.0.1
    |>X-Tomcat-NG: microsoft.public.windows.vista.installation_setup
    |>
    |>Agreed, however shouldn't enabling memory re-mapping (which if I recall
    maps
    |>the address space above the 16GB line which properly allows hardware
    devices
    |>to map within the first 4GB of address space) solve the issue? Or does
    |>Vista not handle this? I know server does, but does Vista?
    |>
    |>Joe
    |>
    |>|>> Hello,
    |>> Sorry but no. The hardware in the system is reserving the address
    space.
    |>> Since 32-bit processors are limited to 4 gig of address space, hardware
    |>> that requries addressing( like video cards or other devices including
    PCI)
    |>> has to reserve some of the address space, thus limiting the amount of
    RAM
    |>> that is available to Windows. Windows is not reserving that memory, the
    |>> hardware in the system is reserving that space. Since there is a
    |>> limitation of 4 gig of address space and there is overlap, the amount of
    |>> RAM that can be addressed is reduced by the amount of address space the
    |>> hardware requests.
    |>> Thanks,
    |>> Darrell Gorter[MSFT]
    |>>
    |>> This posting is provided "AS IS" with no warranties, and confers no
    rights
    |>> --------------------
    |>> |>Thread-Topic: Vista 32bit does not recognise 4GB memory
    |>> |>thread-index: Acdd5zio4a06f0dITDOOQxEcwejddQ==
    |>> |>X-WBNR-Posting-Host: 67.35.76.243
    |>> |>From: =?Utf-8?B?cm9nZWxhaA==?= <>
    |>> |>References: <>
    |>> |>Subject: RE: Vista 32bit does not recognise 4GB memory
    |>> |>Date: Sat, 3 Mar 2007 14:56:47 -0800
    |>> |>Lines: 41
    |>> |>Message-ID: <>
    |>> |>MIME-Version: 1.0
    |>> |>Content-Type: text/plain;
    |>> |> charset="Utf-8"
    |>> |>Content-Transfer-Encoding: 7bit
    |>> |>X-Newsreader: Microsoft CDO for Windows 2000
    |>> |>Content-Class: urn:content-classes:message
    |>> |>Importance: normal
    |>> |>Priority: normal
    |>> |>X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.2757
    |>> |>Newsgroups: microsoft.public.windows.vista.installation_setup
    |>> |>Path: TK2MSFTNGHUB02.phx.gbl
    |>> |>Xref: TK2MSFTNGHUB02.phx.gbl
    |>> microsoft.public.windows.vista.installation_setup:11232
    |>> |>NNTP-Posting-Host: TK2MSFTSBFM01 10.40.244.148
    |>> |>X-Tomcat-NG: microsoft.public.windows.vista.installation_setup
    |>> |>
    |>> |>
    |>> |>
    |>> |>"GreatGuruMemsahib" wrote:
    |>> |>
    |>> |>> I am having a problem with Windows Vista 32bit. I have installed 4GB
    |>> Kingston
    |>> |>> 667 memory on an ASUS P5B Deluxe motherboard. Vista only recognises
    |>> 3GB
    |>> of
    |>> |>> the memory. I understand that certain devies require memory mapped
    |>> access. I
    |>> |>> have a 256MB video card that will take up sojme of the available
    |>> address
    |>> |>> space. I also understand that 32bit versions of Vista limit the
    total
    |>> |>> available memory to 3.12GB.
    |>> |>>
    |>> |>> I have attempted to enable the memory remapping feature in the BIOS
    |>> setup.
    |>> |>> When I return to Vista, it only recognizes 2GB of memory.
    |>> |>>
    |>> |>> Is there any way around this problem other than installing the 64bit
    |>> version
    |>> |>> of Vista?
    |>> |>>
    |>> |>> In addition, if installing the 64bit version of Vista, will all of
    my
    |>> |>> applications run successfully? I do have a few custom business apps
    |>> running
    |>> |>> and I do not know whether they have drivers for 64bit operation.
    |>> |>>
    |>> |>> Thanks I realize that all of this is quite complex, but I am
    curious
    |>> as
    |>> to
    |>> |>> whether there are any answers out there.
    |>> |>
    |>> |>It is not a problem. You can look in your BIOS and see if you have
    4GB.
    |>> The
    |>> |>operating system has to have some space allocated for it to do its
    work;
    |>> it
    |>> |>needs buffers for I/O and needs to have memory to allocate for the
    data
    |>> |>structures it needs to keep track of things. The 3.12GB is the amount
    of
    |>> |>space that can be allocated for your Working Set. Actually, your
    working
    |>> set
    |>> |>in memory at any one time may be less. There may also be other
    programs
    |>> in
    |>> |>memory at the same time; such as your mail agent that periodically
    |>> checks
    |>> for
    |>> |>mail. Ideally, the operating system tries to keep in memory what it
    may
    |>> need
    |>> |>next. If it doesn't have it in memory then it has to fetched from
    |>> virtual
    |>> |>memory. That may mean that other parts of your working set that are
    not
    |>> |>likely to be needed are overlaid by the code bing fetched.
    |>> |>
    |>> |>I don't think you need to go to 64-bit just because 64-bit can address
    |>> 2^64
    |>> |>locations. If you have only 4GB of memory and a 64-bit operating
    system
    |>> there
    |>> |>will still be the same allocation for the operating system. If you add
    |>> memory
    |>> |>over 4GB then you will need a 64-bit operating system to access the
    |>> memory
    |>> |>above 2^32 locations.
    |>> |>
    |>>
    |>
     
    Darrell Gorter[MSFT], Mar 5, 2007
    #6
  7. GreatGuruMemsahib

    Joe Guidera Guest

    That's what I meant. Does Vista support PAE? I believe for example that XP
    did not (only available in Windows Server) so the maximum amount of usable
    memory was 3GB.

    Joe

     
    Joe Guidera, Mar 5, 2007
    #7
  8. GreatGuruMemsahib

    vasu Guest

    Pl. check this KB article:
    http://support.microsoft.com/kb/929605/en-us
    "If a computer has 4 gigabytes (GB) of random-access memory (RAM) installed,
    the system memory that is reported in the System Information dialog box in
    Windows Vista is less than you expect"

    For Windows Vista to use all 4 GB of memory on a computer that has 4 GB of
    memory installed, the computer must meet the following requirements:
    • The chipset must support at least 8 GB of address space. Chipsets that
    have this capability include the following:
    • Intel 975X
    • Intel P965
    • Intel 955X on Socket 775
    • Chipsets that support AMD processors that use socket F, socket 940, socket
    939, or socket AM2. These chipsets include any AMD socket and CPU combination
    in which the memory controller resides in the CPU.
    • The CPU must support the x64 instruction set. The AMD64 CPU and the Intel
    EM64T CPU support this instruction set.
    • The BIOS must support the memory remapping feature. The memory remapping
    feature allows for the segment of system memory that was previously
    overwritten by the Peripheral Component Interconnect (PCI) configuration
    space to be remapped above the 4 GB address line. This feature must be
    enabled in the BIOS configuration utility on the computer. View your computer
    product documentation for instructions that explain how to enable this
    feature. Many consumer-oriented computers may not support the memory
    remapping feature. No standard terminology is used in documentation or in
    BIOS configuration utilities for this feature. Therefore, you may have to
    read the descriptions of the various BIOS configuration settings that are
    available to determine whether any of the settings enable the memory
    remapping feature.
    • An x64 (64-bit) version of Windows Vista must be used.

    Then it also talks of
    PAE-mode-induced driver compatibility issues.

    Pl. check the KB article for complete reading.
    http://support.microsoft.com/kb/929605/en-us

    vasudev
     
    vasu, Mar 5, 2007
    #8
  9. GreatGuruMemsahib

    Joe Guidera Guest

    Hmm, that article would seem to suggest that PAE is, in fact, supported on
    Vista (and it must be automatic as I don't see a reference to modifying the
    boot to enable it). Interesting. But to some extent the article is also
    self contradictory. I.E. it says you need one of the name chipsets but then
    goes on to say that you need a chipset that supports the X64 instruction set
    (which if you had you shouldn't need PAE if you're using Vista X64 as it
    should be using a flat address space capable of much larger than 4GB of
    address space).

    Digging back in memory PAE/MMIO and re-mapping above the 16GB line only
    applied to X32 (as the 32-bit word had a maximum value of 4GB).

    Thanks for the article reference. Still isn't real clear (and to be honest
    my question was more academic than otherwise). If MS is reading this they
    should perhaps clarify the article.

    I believe what they were getting at was you needed EITHER a chipset and BIOS
    that supports remapping above the 4GB line (e.g. PAE) OR a chipset with X64
    instruction support (meaning you have an address space larger than 4GB to
    work with to begin with). If either of the above is true Vista should
    correctly report the installed memory of 4GB. It also goes on to warn that
    while the hardware might properly support it, and the OS might properly
    support it, your drivers might not <g> More likely in a 32-bit than in 64.

    Cheers,
    J
     
    Joe Guidera, Mar 6, 2007
    #9
  10. GreatGuruMemsahib

    Vasu Guest

    Yes Joe, in fact such behavior was also seen in XP also when 4GB RAM was
    used.
    Also check this article http://support.microsoft.com/?kbid=929777, which
    also provides an update for systems showing error when Vista installed on
    system more than 3GB.

    regards
    vasudev
     
    Vasu, Mar 6, 2007
    #10
  11. GreatGuruMemsahib

    Tom Lake Guest

    No, it's not automatic. You can't use a simple text editor to change
    boot.ini
    and enable it as you could in XP, though.
    You can use VistaBootPRO (available free at the link below) to set it.

    http://www.pro-networks.org/vistabootpro/

    Tom Lake
     
    Tom Lake, Mar 6, 2007
    #11
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.