When can I use all 8gigs of my memory MS???

Discussion in 'Windows 64bit' started by Defjr, Mar 30, 2008.

  1. Well, it's nothing I'm likely to tweak if I can avoid it, but I certainly
    see a bunch of folks who routinely run a bit more than that, trying to
    extract the last possible bit of performance out of their machine.
    Personally, on my one machine that has the issue, I've just ordered a pair
    of 1GB DIMMs for it, since I had 4x512's in it. It's just a Windows Home
    Server box, it doesn't need more than 2GB. Actually probably OK at 1GB, but
    it seemed a bit tight, so...
    Charlie Russel - MVP, Apr 4, 2008
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  2. Defjr

    Zootal Guest

    On one of my boards, I had to lower the voltage to get the memory to run
    stable. In yet another, I have 1066 memory in a board that supports 1066
    memory, but I have to run it at 800 because I can't figure out how to make
    it stable at 1066. Go figure....
    Zootal, Apr 5, 2008
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  3. Out of curiousity, I dug out the manual for my Asus M2N32-SLI - it actually
    has a table of memory products that describes what brands and serial numbers
    supports 800Mhz in how many slots.

    That table is probably seriously out of date by now, but it shows how tight
    the specifications my actually be. I think this is well worth to notice (and

    Tony. . .
    Tony Sperling, Apr 5, 2008
  4. And it corresponds to the test reports on the website. I suspect that folks
    look there for the memory products that are supported but fail to notice how
    much was tested. I know I didn't take that seriously enough and learned the
    hard way not to assume that just finding the specs for the ram I wanted to
    use did not mean that I could fill all the slots with it without taking
    further steps to get it working.
    Colin Barnhorst, Apr 5, 2008
  5. You are absolutely right, Colin - the section of the manual that describes
    the memory support clearly states, and in several places, that the board
    supports up to 8GB 800Mhz - only in that table is it shown that you need
    specific quality units to have it support more than two slots of up to 2GB
    each! So, true enough, but a low precision form of truth, perhaps.

    I will commit Charlie's [acquired?] Voltage trick to my own personal and
    frightfully slow memory, one fine day it may solve an 'issue'?

    Tony. . .
    Tony Sperling, Apr 5, 2008
  6. Defjr

    Defjr Guest

    First off, I want to say thank you to all of you who have replied, and
    especially Mr Russell. I did not intend to come off as yelling at you guys,
    but MS. Now then, I used the voltage "trick" and now all seems to be well
    with 1 exception:
    On the Vista compatibility page of this website it lists the Hauppauge
    PVR150MCE/ PVR500MCE tuner as Compliant, and works with 64 bit, and it
    does.....if you have less than 4 gigs of memory(why that magic number keeps
    showing up is beyond me). Hauppauge says they will not be looking into the
    problem anytime soon, as they are working on their "new" product line, but
    has offered to RMA the card for a new model that will work(all beit a single
    tuner model).
    The reason I have been upset with MS is due to the way they hand out the
    logo of works/ certified for Vista without requiring the manufacturer to show
    the actual test. In this example they would have seen Hauppauge did the
    origonal test for the logo on that product with only 512M of RAM?!?! Who in
    the world would use a 64bit OS with that low of RAM? Isnt the whole purpose
    of 64 bit for more memory allocations? Anyone know why you cant install Vista
    64 with more than 2 gigs of RAM to start? I origonally attempted installing
    with 8, then 6, then 4, and finally successfull with 2. Upon installing SP1 I
    could then re-install the memory and moved the voltage up as suggested and
    all worked fine?!?
    Again thanks to those who sent in sugestions, and hopefully this will all be
    done soon.
    Defjr, Apr 11, 2008
  7. Defjr

    Defjr Guest

    In case anyone was wondering the specs:

    EVGA 780i mobo
    Intel core 2 Quad Q6600
    Corsair 2x 2048 XMS PC6400 @800Mhz RAM per kit(2 kits)
    2 Raptor 150 HDDs in Raid 0
    EVGA 9800 GX2 GPU
    Audigy 2 ZS Platinum sound
    Toughpower 1200W PSU
    Hauppauge PVR500MCE (does not work without disabling memory)
    Pioneer BD/DVD/CD multi drive (cant remember the model)
    All liquid cooled CPU, GPU, HDDs, RAM, with no overclocking
    Defjr, Apr 11, 2008
  8. Defjr

    Don Guest

    I installed Vista Ultimate 64 bit, with 4 sticks of 1gb each Corsair PC8500
    ram, in my EVGA 780i mb, with no problems. ( Prior to SP1 ).

    Not sure why some have a problem, and some don't, but I can say it worked
    fine for me.
    Don, Apr 12, 2008
  9. I don't think most regulars here loose much sleep if someone is yelling on
    occasion, this is an unusually reasonable and level-headed community with a
    direct aim at helping out. What isn't the best approach, is starting out
    yelling "MS bug!" over something that MS clearly has no control over - and
    this isn't even that we are in any significant way pre-determined for
    protectiveness towards MS, you will find quite a lot of critisism here too,
    but for some strange reason almost everybody wants to keep it on-track -
    probably because de-railings turn out to be hard to handle, in most cases.
    Personally, I agree with you on this, this comment really ought to have
    appeared in your original post - we have debated the 'glaring' changes that
    was made in the WHQL requirements since Vista was released - mostly the
    disappearing original requirement that [Certified for Vista] had to imply
    that it would not be 64bit incompatible, but it has not been on a daily
    exchange here lately.

    On the other hand, 64bit computing is a moving target and it is not many
    months ago that the general PC professional would regard putting a TV card
    onto a 8GB machine as a somewhat alien idea, but I agree - this is not any
    credit for Hauppauge, they have no reason to feel proud and I think it's a
    great idea that MS (or the manufacturer?) should make the tests public.

    Thanks, though, for making your own experiments public - the Voltage trick
    is immensly usefull, I think! Can you think of anything reasonably
    interesting to add about the steps you took, and/or how much you upped the

    Tony. . .
    Tony Sperling, Apr 12, 2008
  10. Defjr

    miso Guest


    Can you venture a guess as to why too much ram effects a video card?
    They are on different buses.
    miso, Apr 12, 2008
  11. I wouldn't really know. To me, this has a look of 'stupidity' about it.
    Since a TV tuner card operates partly by saving streams to files I guess the
    driver could try and set up a default buffer to start from in quick respons
    to someone saying "Hey, I want to record this show!" - the routine, perhaps
    having a 'good-will' kind of attitude, wants to find an optimal size for the
    buffer and then chokes on the amount?

    Hard to say, though. It's not pretty!

    Tony. . .
    Tony Sperling, Apr 12, 2008
  12. Defjr

    Tom Lake Guest

    They share the same address space, though.

    Tom Lake
    Tom Lake, Apr 12, 2008
  13. Defjr

    DevilsPGD Guest

    In message
    Different bus, but shared address space.

    Also, in the area of video cards or other devices which deal with large
    amounts of data, the hardware may also use DMA (direct memory access) as
    well as shared address space.

    For either DMA or shared address space to work, both the hardware and
    drivers have to be capable of addressing all of the RAM currently in use
    by the operating system.
    DevilsPGD, Apr 12, 2008
  14. Defjr

    DevilsPGD Guest

    In message <> Defjr
    2^32 is 4GB. If you're using a 32bit integer for address ranges, you
    can't access memory above 4GB.

    If you're an operating system, this isn't a big deal, you just don't
    offer access to memory above 4GB at all and life is good.

    Applications can usually survive as the operating system's virtual
    memory subsystem already remaps memory requests.

    However, drivers don't have that luxury as they deal directly with
    DevilsPGD, Apr 12, 2008
  15. Defjr

    miso Guest

    Just to be clear here, while 2**32 is 4G, MS didn't see fit to allow
    their 32 bit OS to see 4G. The limit is around 3.2G. In some
    situations, I believe the Intel chip set is the limiting factor
    regarding available memory.
    miso, Apr 13, 2008
  16. Defjr

    DevilsPGD Guest

    In message
    The ~3.2GB limitation is not Microsoft specific, it's an x86
    architectural limitation.

    In general an x86 system can't actually address 4GB of memory, but
    rather, it has 4GB of address space.

    Certain blocks (Parts of 640KB-1MB, hence the old DOS 640KB limit) are
    reserved in all systems, various other hardware needs have their own
    variable address space needs.

    Between your motherboard and video card, you're usually down to about
    3.2GB of address space for physical RAM. With a couple higher end video
    cards, this can be substantially lower.

    There is a hack around the problem, PAE, which is more or less the EMS
    of the 2000 era, but it requires all hardware and kernel mode drivers to
    support PAE, so in practice it's only seen on servers (and isn't
    included in any Microsoft desktop operating systems)
    DevilsPGD, Apr 13, 2008
  17. Defjr

    Zootal Guest

    IIRC, chipset memory limits occur in powers of two, at least for newer
    chipsets. A few Intel sets have a 2GB limit, a lot of sets have a 4GB limit,
    and more have an 8GB limit. I'm pretty sure oddball limits like 3.2GB are OS
    Zootal, Apr 13, 2008
  18. That is NOT something MS did at all. It is the BIOS on your mobo that is
    reserving the space. My systems show from 2.5GB to 3.5GB, depending on the
    hardware on the system. There is simply no such thing as a 3.2GB limit.
    The often quoted knowlegebase article that gives 3.12GB does so as an
    example in order to illustrate how the memory available for user programs is
    calculated. It is no more valid for your system than a TurboTax example
    would be for your real return.
    Colin Barnhorst, Apr 13, 2008
  19. The "oddball" amounts are not OS limitations and they are not oddballs.
    They result from how the BIOS allocates memory-mapped IO for the devices
    installed on the system. The mobo manufacturer is responsible for this, not
    MS. Since hardware varies from system to system, so does the amount
    reserved for the memory-mapped IO.
    Colin Barnhorst, Apr 13, 2008
  20. Yes - and is this also not proving that re-mapping the BIOS, to make 4GB
    visible (to the user), isn't giving the system any more memory to work with
    (unless there is more than 4GB installed)? The re-mapping relocates the PCI
    memory to make the rest visible, but the space it inhabited in the old
    location is still consumed by the same amount somewhere else.

    Tony. . .
    Tony Sperling, Apr 13, 2008
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