PC not recognizing full RAM (Win XP)

Discussion in 'Computing and Networks' started by #12, Nov 7, 2013.

  1. #12

    Thread Starter Expert

    Nov 30, 2010
    Same problem as DS8, different computer. I have a Dell Dimension 8250 with XP Home Edition and (4) 1 gig RAM sticks. Any 2 sticks will work in either pair of sockets, but when I install 4 sticks, the computer will not boot.

    Is this inherent in that computer or that OS? (I can't seem to find a BIOS setting that applies to the problem.) Anybody know something about getting an XP to recognize 4 gigs?
  2. strantor

    AAC Fanatic!

    Oct 3, 2010
    I read somewhere the max a 32bit OS will recognize is 4gb. I don't know if that's exact. My "top of the line" 32bit xp laptop shows 3.48gb of ram. Maybe that's the actual max. Have you tried 3gb worth of sticks?
    #12 likes this.
  3. Dr.killjoy

    Well-Known Member

    Apr 28, 2013
    Are the stick the same or random ???
    #12 likes this.
  4. bertus


    Apr 5, 2008
    #12 likes this.
  5. #12

    Thread Starter Expert

    Nov 30, 2010
    Bertus gave the definitive answer. Thank you. End of discussion.
  6. Litch


    Jan 25, 2013
    Not really, the fact it isn't booting would suggest that it's a motherboard limitation not an operating system limitation.

    There are many types of RAM; namely single rank, dual rank (and quad rank in more recent chips), the chipset on the motherboard (Northbridge) is the memory controller and has limitations in what types and combinations of chips are used and how much total RAM is placed in the system.

    Eg. if you have 4 x DR RAM chips, the Northbridge may only be able to address 2 x DR and 2 x SR, thus POST will fail.

    If the limitation was the OS (eg. 32-bit OS without PAE) then it would still boot but only be able to address between 2.7 and 3.5 of the 4GB (Depending on how it can reference the 4GB address space and if any memory is shared with the on-board video card, if present).


    From the user guide d8250mat.pdf:

    Code ( (Unknown Language)):
    1. Memory
    2. Type PC800 or PC1066 RDRAM (non-ECC)
    3. Memory connectors four
    4. Memory capacities 64-, 128-, 256-, and 512-MB non-ECC
    5. Minimum memory 128 MB
    6. [B][U]Maximum memory 2 GB for PC800[/U][/B]
    7. 1.5 GB for PC1066
    That is your definitive answer.
  7. electronis whiz

    Well-Known Member

    Jul 29, 2010
    Yah I agree I'm pretty sure max for XP was like 4GB or less, Many dell systems are also pretty lousy when it comes to ram capacity. I have an old 4550 P4 2.5GHZ system, 2 DDR3 slot max 1GB 512 MB per. Seems odd to me the setup is this way, but nothing you can do. Why after my current dell fails i'm never using dell again.