Usable Memory

Discussion in 'PC Hardware' started by MrTsquare, Jan 26, 2015.

  1. MrTsquare

    MrTsquare Guest

    I have a relatively new build from Aug14 (Win7-64/ASUS-Pro97/4790K/770)
    with 32GB installed memory. Everything is running fine. Just noticed
    in the "Windows Experience Index" that I have 32GB installed but only
    16GB useable. I thought that Win7-64 handled up to 32GB, else I wouldn't
    have bought 32GB. OPENHARDWAREMONITOR also only sees 16GB. I mean I
    guess I really don't need the other 16, but why aren't they "useable???

    MrTsquare, Jan 26, 2015
    1. Advertisements

  2. MrTsquare

    Paul Guest

    There are a couple possibilities.

    1) Bad channel on memory controller.

    Test with one stick of RAM. Try the stick of RAM in
    each of the four DIMM slots. If a slot doesn't work, a
    pin could be bent or dirty.

    You're supposed to do that when the motherboard is new.

    I carried that out on my new build in August, while
    the system was still sitting on the kitchen table. I
    tested each slot individually, to make sure they all worked.
    When finished those tests, I installed all the RAM and did
    one final test that all the memory worked.

    Use for a standalone bootable
    memory testing program. It should report the amount of
    memory it is testing, and the current version can test
    a lot of RAM. Scroll half way down that web page, to find
    the download links.

    2) Windows boot.ini or binary BCD, has a provision for
    disabling memory. You can dial down the amount of memory
    used by Windows, instead of using the whole thing.

    We needed to do such things on Win98, where the OS was
    only really 100% stable with a 512MB setting. Later OSes
    do not have that kind of issue, but the capability still
    exists if you need to use it.

    Paul, Jan 26, 2015
    1. Advertisements

  3. MrTsquare

    MrTsquare Guest

    Thanks, Paul. I'll get to doing what you suggest, but... How can
    Windows see the whole 32G if there is an error in one of the

    MrTsquare, Jan 27, 2015
  4. MrTsquare

    Paul Guest

    Actually, RAM is weeded out by the BIOS. The operating
    system simply assumes all RAM is good.

    The BIOS first reads the SPD EEPROM on each DIMM, to
    get the declared size. But the BIOS also does traditional
    peek and poke testing, to verify the actual size of the

    That handles cases of gross problems with a DIMM. Such
    as the declaration SPD EEPROM being incorrect. One poster
    here, had a 1GB stick with a 2GB SPD chip on it, and the
    BIOS knew right away the DIMM was 1GB. Because it used
    the historical peek and poke method to determine it
    wasn't a 2GB stick.

    Similar things happen, when a 2GB high density stick,
    is used with a chipset lacking addressing support for such.
    The BIOS figures out that only 1GB of the stick stores anything,
    and uses that detected size when setting up the memory map.
    Then, the OS uses that memory map without modification.


    Some utilities, when they're telling you about your
    installed memory, they just read the SPD on each DIMM
    and work out the size that way. That's why a utility can
    say "I see 32GB of sticks", but Windows registers 16GB. The
    BIOS knows what is going on, and most of the time, the BIOS
    turns on just the right amount of address space. I consider
    it amazing, how many motherboards do not crash due to
    incorrect memory sizing. The BIOS is damn good at what it
    does. That's the observed evidence.

    So your BIOS knows only 16GB works, for some reason.
    Your job is to figure out why, and correct it.

    While the boot.ini has a field to control memory
    usage, it is unlikely to be applied on a brand new install.
    Only if the user has been fooling around with that setting,
    would it get set to an inappropriate value. It doesn't get
    that way on its own. On a brand new install, that field is
    not defined or used. (But if you're working on some
    other persons system, you have to consider them having
    screwed around with that, when checking their system
    for them.)

    Paul, Jan 27, 2015
  5. MrTsquare

    Yousuf Khan Guest

    Strangely not all Windows 7 64-bits are equal. It sounds like you have
    Win7 Home Premium. That has a 16GB max memory limit.

    If you go to Professional, Enterprise, or Ultimate, you'll be able to
    use upto 192GB!

    Max memory limits for 64-bit Windows 7 | ZDNet
    Yousuf Khan, Jan 27, 2015
  6. MrTsquare

    MrTsquare Guest

    WELL THAT REALLY SUCKS!! Thankyou Yousuf and I do have the Home-Premium
    version. Good info and had I known I certainly would not have bought
    that much RAM.

    MrTsquare, Jan 28, 2015
  7. MrTsquare

    Paul Guest

    Wow. I didn't know there was that low a limit.

    My best machine here has only 16GB.


    There is a canonical table for memory limits here. Scroll down
    to find OS specific ones.

    Maybe the Windows 10 upgrade will fix the issue for you,
    but at the current time, we don't know what upgrade paths
    will be offered (whether Win7 Home Premium would become
    Win10 Pro for example). I expect there will be an arcane
    upgrade table, to annoy and irritate. The memory table
    doesn't have a Windows 10 entry in it, but it should
    be "at least as good as Windows 8".

    The other possibility, is an "Anytime Upgrade" to change
    the Windows 7 version, but I don't know whether you can
    still purchase those or not.

    Paul, Jan 28, 2015
  8. MrTsquare

    Yousuf Khan Guest

    Microsoft's Windows offerings often leave a lot to be desired. Now,
    these limits are entirely arbitrary, and it has nothing to do with
    technical limitations, they are entirely marketing-driven. Encouraging
    you to buy the next higher version of Windows.

    There might be a way to bypass it, but I wouldn't count on it.

    Fix the Maximum Amount of Memory Usable by Windows 7 64-bit

    Yousuf Khan
    Yousuf Khan, Jan 28, 2015
  9. MrTsquare

    Tom Thompson Guest

    From the comments following the article in your link it appears that
    while Windows can identify my 32G is would cap it at 16G due to the
    marketing limitation.

    Tom Thompson, Jan 28, 2015
  10. MrTsquare

    Tom Thompson Guest

    Well, no real need for the other 16 at this point but just disturbing to
    learn of the artificial limit. When I firts did the build I bought and
    installed Win8.1 but it ticked me off so bad, even with Clasasic Shell
    that within a couple of days I went over to Frys and got another copy of
    Win7-64. So, if Win10 proves to be worthwhile and with the potential
    free upgrades being discussed that may be to way to go. Also hearing
    that Win10 may be MS's next shot at rental-ware so that is kindof
    upsatting as well.

    Tom Thompson, Jan 28, 2015
  11. MrTsquare

    Flasherly Guest

    16G is a healthy amount all except for some pretty intensive apps.
    Discounting what all else is limited in Microsoft's benign designs, at
    least that one is more oriented within their own ranks, no doubt,
    aimed at industrial and corporate usages, and less the average PC for
    home usages. Photo editing and a few virtual machines come to mind as
    extremes for the latter instance. I've, still, 2G running W7, in as
    much having seen actual benefits for eclipsing W98, on XP, with that.
    And that's going really too far back, be as and for what it is, to
    make, too readily, credible claims upon W7, to 4G to 8, 8G to 16, much
    less 16G to 32G;- point being, what for the sake of precision, in
    hell, does one do with 32G once one has it? And for an optimal, I'd
    wonder, is a _sustainable_ one for upon which W7 might run, at an
    optimal, for the least amount of populated RAM.

    Arbitrarily market driven was, in likelihood, before -- less apropos
    to lower cost, stable home builds these days -- were it not altogether
    for a general geneses into handheld subscription devices in favor of a
    diminutive wholesale PC market, at one compared to yesteryear's volume
    sales. Tech is lean and pretty much mean for all, with Microsoft's
    share of floundering, no less being a fact others have to deal with;-
    and, they're all having the same problems with the newer crop of
    handhelds holding up, constructurally and functionally, to where the
    market share for their updated improvements are being relinquished, by
    public demand, in deference to prior purchases. ($800US entry
    tablets, indeed. ...& M$, of course, with their latest free W10
    offerings to place upon it.)
    Flasherly, Jan 28, 2015
  12. MrTsquare

    Paul Guest

    What you can try if you like, is DataRAM RAMDisk.

    The "RAMDisk Lite" version is free for RAM Disks up to 4GB
    in size. If you like it, you can pay the fee and have up to
    64GB (in your case, probably a bit less, as you have 16GB
    of conventional RAM).

    The idea is, the Windows memory license applies to Ring 3.
    Whereas Ring 0 (driver and kernel), does not have that limit.
    Programs in Ring 3 are subject to the memory license.

    In the case of that RAMDisk, there is a driver that runs
    in Ring0. And that means, with your 32GB RAM purchase,
    you can have the 16GB cap for Windows programs, leaving
    the other 16GB available for a RAMDisk. With the free
    version, you could do 16+4, and with the paid version
    of the RAMDisk software (license key), you could do

    I use that RAMDisk here, on WinXP. I bought 8GB of RAM.
    WinXP x32 can only use 4GB of that. Leaving the other
    4GB unused. But WinXP SP3 runs the memory mapper in PAE
    mode, so all of that memory is mapped. It's just a matter
    of something using it. And the driver trick is a means
    to use it. So my OS uses 4GB, while the RAMDisk uses
    the other 4GB.

    Now, you have to think about what will happen to that
    RAM during sleep, hibernation, shutdown. Sleep should be
    fine. Hibernation on my machine, only stores the lower 4GB,
    so the RAMDisk contents would get lost without help. I allow
    them to get lost on purpose (as I don't want to wait for
    4GB of stuff to be written out to disk). The RAMDisk does have
    a tick box setting, to store the RAMDisk at shutdown.

    Later, if something goes to use the RAMDisk after recovery
    from hibernation, the partition appears to be corrupted.
    So you have to "format" it, or turn it off and on again,
    to refresh the formatting. But other than those details,
    it's a way for me to get some kind of usage out of my unused

    When I run some other OSes here, I can use the whole 8GB, so
    it isn't a complete loss. I have other x64 OSes to use, like

    The RAMDisk can grab memory from the Windows-owned memory
    area (AWE). Or it can grab memory from above Windows (unused
    PAE area). It won't use both at the same time, so you have
    to decide which area to use. Since nothing else can use your
    high memory area, giving it the PAE area is a natural fit.

    When I benchmarked my RAMDisk with HDTune, I get 4GB/sec transfer
    rate. Both my machines give pretty well the same transfer
    rate value. So something software related, caps the rate.
    I think the STREAM benchmark gives a better result than that,
    as would the memtest86+ metric for memory speed (it has a transfer
    test it runs).

    Paul, Jan 28, 2015
  13. MrTsquare

    MrTsquare Guest

    Thanks, Paul. Something to think about.

    MrTsquare, Jan 28, 2015
  14. MrTsquare

    MrTsquare Guest

    And Bill Gates at one time thought we would never need more than a
    Meg... ;<)

    MrTsquare, Jan 28, 2015
  15. MrTsquare

    Flasherly Guest

    As well envisioning a "flat" picture screen on every household wall.

    It was Word that got me, up round about the NSA, now, in Utah, where
    Word Perfect dominated things.

    MS, meanwhile, in CA, was behind literally one-way mirrors studying
    peoples' faces, quirks and body language, for Word for Windows
    development. 'Dem boys are taking themselves serious, I may have

    Things, of course, never stay the same.
    Flasherly, Jan 29, 2015
  16. MrTsquare

    MrTsquare Guest

    Wish I had bought their stock then.

    MrTsquare, Jan 29, 2015
  17. MrTsquare

    Flasherly Guest

    Or, sold their stock...when, being the name of that game.
    Flasherly, Jan 29, 2015
    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.