4GB DDR memory not showing up in XP

Discussion in 'Windows Desktop Systems' started by canadian_divx, Dec 26, 2005.

  1. canadian_divx

    canadian_divx Canadian_divx

    i have installed windows XP pro on an amd X2 computer, i have also put in 4GB of DDR in the system but windows in the system properties only sees 3gb

    the bios sees 4gb. and im just wondering if there is a limit in XP or someway that i can get it to change to show the 4gb because i want to sell this system.

    interestingly enough.
    i will run a belarc on the system and it shows 3072 of total but then lists 4 banks of 1gb modules of ddr. odd

    memtest also sees 4gb and i have run a total of 28 passes on it with no errors.

    does anyone know how i can get windows XP to display 4GB DDR?
     
  2. Heeter

    Heeter Overclocked Like A Mother

    Messages:
    2,732
    WindowsXP is designed to see only 4gigs of ram. Since it counts the pagefile as ram first (1/4 of your Ram, you case= 1gig) Then counts the rest of the ram sticks to complete the amount to 4gig. Disable your pagefile to list all 4 gigs.

    Win 2003 does not have this problem as it is designed to work with 18gig or 20 gigs, or something like that.

    Heeter
     
  3. Heeter

    Heeter Overclocked Like A Mother

    Messages:
    2,732
    If you don't mind answering, Might I ask why you need 4gig of RAM?

    Heeter
     
  4. canadian_divx

    canadian_divx Canadian_divx

    to tell you the truth. its to sell it.

    i had the extra memory around so i put it in and its fast as hell. but i want to ditch the system so i can move and to the people around here they think the bigger the number the better.
     
  5. ShepsCrook

    ShepsCrook Red Sox Fan!

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    Have you tried updating the bios on your mobo? It might be reporting to Windows wrong. Also, Windows XP Pro SP2 has a maximum of 4GB of ram I believe. Whereas XP 64bit and up do I think 16GB
     
  6. canadian_divx

    canadian_divx Canadian_divx

    wow how rude of me. im sorry

    thank you for the responce so quickly.

    but i set the system to no paging file and it still shows the 3gb. odd.

    any other ideas?
     
  7. canadian_divx

    canadian_divx Canadian_divx

    yes that was the first thing i tried. the bios is the most current and i didnt see any betas on there site.
     
  8. canadian_divx

    canadian_divx Canadian_divx

    any other ideas.

    im searching through the MS patch becuase on an HP site they referenced one but the link was dead.
     
  9. Perris Calderon

    Perris Calderon Moderator Staff Member Political User

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    ya, it's a bios and a compatibility problem.

    there are a couple of things going on, there's a conflict casued by legacy 32-bit compatibility, and there are device issues

    the processor only has 4 gigs of address space, it can't address more

    memory and all device address spaces has to be mapped below 4GB. When 4GB of memory is installed in a machine there's a conlict between the physical memory and some devices that need address space.

    for instance, Video memory has to be addressable by the processor...it's got to be mapped into some of the 4 gigs of processor address space even when the video card has it's own memory.,,this wouldn't be the case if the card also had it's own processor, but the bios would have to know or see that processor.

    a card that carries 128MB of memory will need the same of processor address space.

    most BIOS resolve this problem is by reserving a hole in memory address at the top of the 4GB range. it's called the “PCI Hole”, which exists below your 4GB and it ensures all 32-bit software can reach those addresses without an address confilct

    The physical memory that's hidden isn't usable by the operating system software and therefore is “missing” from the system
     
    Last edited: Dec 28, 2005
  10. canadian_divx

    canadian_divx Canadian_divx

    ok there is an option for a memory hole in the bois. if i set that to the 4gb or just over will i see it or is this a hopeless thign to get to work in XP pro????
     
  11. canadian_divx

    canadian_divx Canadian_divx

    ok it did nothing. but on memtest it slowed down the memory by about 300mbps
     
  12. canadian_divx

    canadian_divx Canadian_divx

    is it possable to get XP to show this? does anyone know or is it just one of thoes windows things.
     
  13. Perris Calderon

    Perris Calderon Moderator Staff Member Political User

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    I'll attach a pdf for you to read later, I'm on a slow connection that won't upload right now, have a read when I post it

    actually, I think this "fix" first appeared in sp2, so if you go to sp1 the os might see it.

    I don't know though
     
  14. Perris Calderon

    Perris Calderon Moderator Staff Member Political User

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    here ya go
     

    Attached Files:

  15. canadian_divx

    canadian_divx Canadian_divx

    ok cool i will check back later for the pdf. thanks man
     
  16. canadian_divx

    canadian_divx Canadian_divx

    hmm the PAE option seems intresting but it does not want to work
     
  17. Admiral Michael

    Admiral Michael Michaelsoft Systems CEO Folding Team

    The more ram the better... yes! BUT 4GB is pushing it. Even 3GB is a good amount to sell with.