Win7 64bit not seeing all 8gb of ram

Discussion in 'alt.windows7.general' started by Bob H, Dec 27, 2010.

  1. Bob H

    Bob H Guest

    I have just updated my system with another 4gb of ram bringing it upto
    8gb and although the bios sees all 8gb, win7 64bit does not and says
    3.5gb available
    Or have I mis interpreted that?

    Thanks
     
    Bob H, Dec 27, 2010
    #1
    1. Advertisements

  2. Bob H

    R. C. White Guest

    ?Hi, Bob.

    Are you SURE you are booted into 64-bit Windows? Many computers with 64-bit
    CPU and other hardware are delivered with 32-bit Windows pre-installed by
    the vendor. Since peripheral manufacturers drug their feet for years and
    delayed delivery of 64-bit drivers, this made sense for a while, but now
    those drivers are generally available - and often included in the Win x64
    packages. But many 64-bit computers still come with 32-bit Windows
    installed. Because of hardware limits, 32-bit OSes cannot use more than 4
    GB RAM, and some of that address space is used to support devices and
    peripherals. Hardware configurations vary, but 32-bit Windows typically
    will report no more than about 3.2 GB available to the system. That sounds
    like your situation.

    WHERE are you seeing that "3.5gb available"? On the System Properties page?
    Which line on that page? (Since we can't see your computer, you'll have to
    tell us exactly.)

    Click Start | Control Panel | System to see the System Properties page. In
    the middle of that page, mine shows these two lines:
    Installed memory (RAM): 4.00 GB
    System type: 64-bit Operating System

    What does yours say on those two lines?

    RC
    --
    R. C. White, CPA
    San Marcos, TX

    Microsoft Windows MVP (2002-9/30/10)
    Windows Live Mail Version 2011 (Build 15.4.3504.1109) in Win7 Ultimate x64
    SP1 RC


    "Bob H" wrote in message

    I have just updated my system with another 4gb of ram bringing it upto
    8gb and although the bios sees all 8gb, win7 64bit does not and says
    3.5gb available
    Or have I mis interpreted that?

    Thanks
     
    R. C. White, Dec 27, 2010
    #2
    1. Advertisements

  3. Bob H

    Peter Foldes Guest


    Bob

    The computer itself could be 64 bit but the installed OS is not. Sure sounds like
    that since you posted that it only shows 3.5 gigs of memory.
    Refer to the post by R.C. White

    --
    Peter
    Please Reply to Newsgroup for the benefit of others
    Requests for assistance by email can not and will not be acknowledged.
    This posting is provided "AS IS" with no warranties, and confers no rights.
    http://www.microsoft.com/protect
     
    Peter Foldes, Dec 27, 2010
    #3
  4. Bob H

    Bob H Guest

    I pre ordered Windows 7 last sumnmer and recieved 2 dvd's in one case.
    one is win7 64 bit and the other is win7 32 bit. I installed win7 64bit
    myself, so it was not pre installed by anyone else.

    In Control Panel/System under System which is the 2nd heading down from
    the top, it says:
    Installed memory(RAM) 8.00GB (3.5GB Usable)
    System Type: 64bit Operating System


    Thanks
     
    Bob H, Dec 27, 2010
    #4
  5. Bob H

    Bob Henson Guest

    This will be confusing - two Bob Hs. I'm not very technical, but it sounds
    as though something is helping itself to half your RAM. Could it be that
    you have half of it reserved as a ramdisk, say? I don't even know if it's
    possible to do this (I think it's only possible to use a USB stick), but
    could it be Readyboost?

    Someone will no doubt shoot me down in flames if that's nonsense, but
    hopefully the idea of the memory being reserved elsewhere may have some
    merit, and trigger some thoughts in those technically more savvy than me.
     
    Bob Henson, Dec 27, 2010
    #5
  6. Bob H

    Paul Guest

    It *sounds* like a remapping problem of some sort. But the
    symptoms don't add up.

    The "Installed Memory" report of 8.00GB, sure makes it sound like
    all the RAM made it to the OS. It implies the BIOS has done the
    right thing.

    The 3.5GB number is a puzzle though. It's a value, which sounds like
    a 4GB address space is being offered by the OS, 0.5GB used for system
    busses and video card memory addressing, leaving 3.5GB address space
    for the rest. If you'd used a boot flag that restricted how much
    memory the OS could use, perhaps it would report "4.0GB Usable".
    The question would be, how can you restrict the address space
    and get that exact 3.5GB number ?

    There are perhaps a couple chipsets, where you can install 4x2GB,
    but the bus between the processor and Northbridge, only has 32 bits.
    The datasheet warns, that you can install 8GB if you like, but only
    4GB of address space can be used. But in that case, I don't know if
    it would report "Installed memory 8GB". Maybe the BIOS would be smart
    enough to only report 4GB, because that is all that makes sense.
    The BIOS is not supposed to report anything, that can make the
    OS crash. That would be bad design.

    I don't have an answer, but I'd like to get more info.

    1) If you don't know what processor, and it's Intel, run PIU (Windows version)
    Or, I suppose you could do it all, with step (2)...

    http://www.intel.com/support/processors/tools/piu/sb/CS-014921.htm?wapkw=(piu)

    2) It would be nice to know the chipset used on the motherboard.
    For example, Intel 915 has the 32 bit bus restriction on it, preventing
    access to all RAM.

    http://www.cpuid.com/softwares/cpu-z.html

    (ZIP, 64 bit, no install version. Unzip and run CPUZ.exe or equiv.)

    http://www.cpuid.com/downloads/cpu-z/1.56-64bits-en.zip

    Take a look under the "Mainboard" tab. For example, mine reports

    Model: P5E Deluxe
    Chipset: X48
    Southbridge: ICH8R

    I could download a datasheet for X48, and check the memory
    section, to see if there are restrictions.

    For the Intel 915 chipset, it took me a while to find it the
    first time, but this is their note.

    "Though it is possible to put 8 GB in system by stuffing
    both channels this way, the (G)MCH is still limited to
    4 GB of addressable space due to the number of address
    pins on the FSB."

    So report what you find. It may be possible to install a 64 bit
    processor, a 64 bit OS, on a hobbled chipset like that one. And
    then discover at the last minute, that the *chipset* is the
    culprit. The OS still works fine, but with a 915, you can't
    physically get to the upper half of all that RAM.

    Paul
     
    Paul, Dec 27, 2010
    #6
  7. Bob H

    Chuck Guest

    Not really always true, although there are numerous gotchas. See
    www.geoffchappell.com/viewer.htm?doc=notes/windows/license/memory.htm
    A Microsoft "License" Limitation seems to be the culprit.
     
    Chuck, Dec 27, 2010
    #7
  8. Bob H

    McGrath Guest

    Check this...
    Asus P5 Deluxe p2-13 2.4.2 Memory configurations
    [...]
    Due to chipset resource allocation, the system may detect less than 8GB
    system memory when you installed four 2GB DDR2 memory modules.
    [...]
     
    McGrath, Dec 27, 2010
    #8
  9. Bob H

    ray Guest

    Not strictly true since PAE allows 32 bit systems to access 64gb - though
    each process is still limited to 4gb. But, of course, most MS systems are
    not capable of that. I believe the MS server systems can and, of course,
    Linux is quite capable as well.
     
    ray, Dec 27, 2010
    #9
  10. Bob H

    Ken1943 Guest

    Since we don't know what mobo he is using, everything is just a guess.
    Could be the mobo drivers that were installed.

    KenW
     
    Ken1943, Dec 27, 2010
    #10
  11. Bob H

    R. C. White Guest

    ?Hi, Bob.

    OK. That confirms that you are using 64-bit Win7, so there goes that
    theory.

    As the others have pointed out, you have not yet told us the make and model
    of your computer, or of your motherboard/chipset if you built it yourself.
    Those details should shed a lot of light on the situation. Could you
    include that information in your next post, please?

    As indicated in my Sig, I'm an accountant (and retired, at that), not a
    techie of any kind. So I'm generally better at asking questions than
    providing answers. But if my questions elicit the right information, the
    true techies here should be able to explain what is happening. :^}

    RC
    --
    R. C. White, CPA
    San Marcos, TX

    Microsoft Windows MVP (2002-9/30/10)
    Windows Live Mail Version 2011 (Build 15.4.3504.1109) in Win7 Ultimate x64
    SP1 RC


    "Bob H" wrote in message

    I pre ordered Windows 7 last sumnmer and recieved 2 dvd's in one case.
    one is win7 64 bit and the other is win7 32 bit. I installed win7 64bit
    myself, so it was not pre installed by anyone else.

    In Control Panel/System under System which is the 2nd heading down from
    the top, it says:
    Installed memory(RAM) 8.00GB (3.5GB Usable)
    System Type: 64bit Operating System


    Thanks
     
    R. C. White, Dec 27, 2010
    #11
  12. Bob H

    Bob H Guest

    Ok, the motherboard is an Asus P7P55D Evo, and the ram is 4 x 2gb of ddr3
     
    Bob H, Dec 27, 2010
    #12
  13. Bob H

    Ken1943 Guest

    Nice board. I would get the Intel Driver update utility to see if there
    is a newer chipset driver. Asus also has bios updates. One of them is for
    "memory compatibility".

    You can check which chipset driver is installed ( googled and found this,
    which I never new)

    Here is how to find what version chipset driver you have (once and for
    all)...

    Run Registry Editor (Start -> Run -> regedit -> enter)

    Once in the Registry Editor expand "HKEY_LOCAL_MACHINE"
    Next Expand "SOFTWARE"
    Next Expand "INTEL"
    Click on "Infinst"

    On the right hand side there will be two things to look for.
    First is to make sure the line that says "Install" has the word "success"
    next too it (to the right, under "data" ). This indicates the driver was
    installed correctly.
    Next find the line that says "Version", and that will be your version
    number that was installed.

    KenW
     
    Ken1943, Dec 28, 2010
    #13
  14. Bob H

    Paul Guest

    There are some more weird experiences here.

    http://vip.asus.com/forum/view.aspx..._id=1&model=P7P55D+EVO&page=1&SLanguage=en-us

    I'd want to be doubly sure, the system is really reporting "8GB installed".
    If it wasn't, there could be a bad stick. I'd probably test the sticks
    with memtest86+. Even the response of memtest86+ would be interesting,
    in terms of what it thinks is really "installed". Using memtest, helps
    eliminate Windows 7 as solely responsible. If both environments see the
    same problem, it's a BIOS issue or it's bad memory.

    http://www.memtest.org/ (download is half way down the page)

    Also, go back into the BIOS, and try with Memory Remapping enabled
    and with it disabled. Perhaps one of those options, will cause a
    figure greater than 3.5GB to be reported.

    The purpose of remapping, is to try to make all 8GB report as
    available. It pushes memory, on some quantum boundary, above the
    4GB mark. Some server boards, may choose to do a 2GB/6GB split,
    which makes no difference as long as remapping is working. In
    some cases, the quanta is 256MB, so remapping is on a finer
    granularity (not that it matters). The only time it would matter,
    if the total address space was limited in some way. Some older
    systems, only had 8GB of addresses to work with in 64 bit world,
    and would report "7.5GB available", due to bumping into that limit.
    On more modern systems, that's no longer a problem.

    +-------+ \
    | 5GB | \_______
    | high | / \
    4GB+-------+ / \
    | Bus | \
    | Addr /| \___ Seamless 8GB in virtual address space
    | Video | /
    | RAM | /
    +-------+ \ /
    | 3GB | \_______/
    | low | /
    +-------+ /

    The system busses and video RAM, stay below 4GB, in case some
    DMA needs to be done. Some drivers in the past, have been flaky
    if add-in cards have their buffers above 4GB. And some PCI cards,
    can't do double address cycles, so they're limited to 32 bit
    addresses. The end result, is this restriction for safety,
    of keeping system busses below 4GB physical.

    With 8GB installed, I don't know what a "disabled remap" means.
    It could mean, that any memory which conflicts with bus addresses,
    is simply ignored. With remap disabled, perhaps you get 3.5GB
    from low memory, plus 4GB from high memory. Or, if the BIOS
    loads the registers like Top_Of_Memory wrong, only 3.5GB would
    be visible. In any case, I recommend fiddling with that setting,
    then checking what memtest86+ sees, and check what Windows 7 sees.

    Maybe with all the testing, it'll turn out to be a bad stick
    of RAM.

    Or perhaps you're using XMP RAM (that's a spec for memory, which
    allows automatic setup, outside of the JEDEC feature set). I understand
    that things like XMP, if you have four sticks installed, can disable
    two sticks. (The enhanced speed of the RAM, is only guaranteed with
    two sticks, one per channel, and if you enable XMP, it disables
    the two extra sticks, on the pretense it allows more speed. Disabling
    XMP, means you have to set it up the way you want, yourself.) But that
    still doesn't explain why some tools are claiming 8GB is present.
    If that was working right, the system should report
    4GB present (as the other two sticks are ignored).

    Tools like CPUZ can report seeing all the sticks, as CPUZ
    reads the SPD bus and reads the SPD EEPROM on each DIMM. But that
    isn't quite the same thing, as the BIOS determination of available
    RAM. The BIOS reads all the sticks, and programs the memory controller,
    including the top of memory register, plus the additional
    registers for handling the second chunk of RAM above 4GB mark.
    Windows is pretty well stuck with whatever the BIOS does.
    The BIOS is also tasked with coming up with a working config,
    as Windows is not generally allowed to change it. (The only
    option Windows has, it to forbid the system to use some of the RAM.)

    You can see some options here, for making Windows ignore some
    of the RAM given to it. On WinXP, it would be a simple matter,
    to look in boot.ini and see if some option like that was set (MAXMEM).
    It might be a slight bit harder to do on Windows 7.

    http://msdn.microsoft.com/en-us/library/ff556246.aspx

    Good luck,
    Paul
     
    Paul, Dec 28, 2010
    #14
  15. Bob H

    Ken1943 Guest

    Asus has some good forums. All + 1 for each mobo. Might be worth a shot.
    If you find an answer, please let us know.

    KenW
     
    Ken1943, Dec 28, 2010
    #15
  16. Bob H

    Ken1943 Guest

    That board seems to have memory issues.

    KenW
     
    Ken1943, Dec 28, 2010
    #16
  17. Bob H

    Bob H Guest

    Ok folks an update here with what I have done to solve this minor problem.
    I did some searching on this and found some information which said
    something about going into msconfig/ boot/advanced, and untick 'maximum
    memory'

    I did that, rebooted and now 8gb of RAM is shown in system with no
    amount usable, as before.

    So there you go, a simple fix just like that did the job, and it seems
    the board I have is now not subject to memory problems as someone suggested.

    Thanks to all who replied.
     
    Bob H, Dec 28, 2010
    #17
  18. Bob H

    Roy Smith Guest

    I certainly hope that is a typo.. if there is "no amount usable" then
    how is the pc running?
    Good to hear you got it solved...


    --

    Roy Smith
    Windows 7 Professional
    Postbox 2.1.0
    Tuesday, December 28, 2010 3:07:07 PM
     
    Roy Smith, Dec 28, 2010
    #18
  19. Bob H

    Bob H Guest

    The 'no amount usable' means that what it said before about 3.5gb usable
    is that there is no 'amount usable' now. So the pc is running on full 8gb
     
    Bob H, Dec 28, 2010
    #19
  20. Bob H

    Roy Smith Guest


    Oh I get it now... boy that can be confusing if one isn't paying close
    attention...



    --

    Roy Smith
    Windows 7 Professional
    Postbox 2.1.0
    Tuesday, December 28, 2010 5:05:19 PM
     
    Roy Smith, Dec 28, 2010
    #20
    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.