6gb ram installed (used 4 gb)

Hello,
I've a dell precision 490, ive increase my pc ram to 6 gb, but i see that only my 4 gb are usable,
2gb x 3ram= 6gb ram, operating system 64 bit window 7 ultimate.
ive try to enter to msconfig.exe to change boot but nothing change.Ive update my bios but nothing change too.ive remove and change ram position but same thing I dont know what to do and pleaese need help.Thank You (sorry for my english)
13 answers Last reply
More about installed used
  1. IMO - bad stick. Test with Memtest or the simplest is to pull the RAM and test 1 stick at a time in the 2nd DIMM slot from the Xeon. When it fails to Post/Boot = Bingo!
  2. run memtest to check for bad ram sticks, test them individually.

    If they all pass, then one or two of your ram slots are broken on the motherboard.
  3. Ive done the ram replacemant.
    If i put the new one (2gb smasung)+(2gb qimoda) it works with 4 gb ram,
    if i put the old (2gb qimoda)+(2gb qimoda) it works with 4 gb ram too.
    but if i put (2gb smasung)+(2gb qimoda)+)+(2gb qimoda) it show this:

    Alert! Memory configuration mismatch.
    Please ender Setup for Memory Info details.
    Strike the F1 key to continue, F2 to run the setup utility.
    _
    i press F1 to continue end run in windows and i see that i ve installed 6 gb ram and 4 gb ram are in use.
    PLEASE NEED HELP TO RESOLVE MY PROBLEM.THAKS A LOT
  4. if i press F2 to run setup utility to memory info,
    it show me this tab:
    DIMM 1: 2 GB SIZE; ECC YES; RANK 2; TYPE FBD
    DIMM 2: 2 GB SIZE; ECC YES; RANK 2; TYPE FBD
    DIMM 3: 2 GB SIZE; ECC YES; RANK 2; TYPE FBD
    Installed memory = 4.0gb
    Memory channel mode = dual

    And above this tab sho that:
    None of these fields are changeable
    PLEASE NEED HELP TO RESOLVE MY PROBLEM.THAKS A LOT
  5. bledi said:
    if i press F2 to run setup utility to memory info,
    it show me this tab:
    DIMM 1: 2 GB SIZE; ECC YES; RANK 2; TYPE FBD
    DIMM 2: 2 GB SIZE; ECC YES; RANK 2; TYPE FBD
    DIMM 3: 2 GB SIZE; ECC YES; RANK 2; TYPE FBD
    Installed memory = 4.0gb
    Memory channel mode = dual

    And above this tab sho that:
    None of these fields are changeable
    PLEASE NEED HELP TO RESOLVE MY PROBLEM.THAKS A LOT



    Please is anyone that can resolve my problem??
  6. Problem, you are Mix-Matching RAM in the same primary channel. Best solution get a third stick of (2gb qimoda). The BIOS is reading the miss-matched JEDEC and shutting-down the 'odd' stick.

    (2gb samsung)+(2gb qimoda)+(2gb qimoda)

    Solutions:
    1. Replace the Samsung with a stick of '(2gb qimoda)'.
    2. Use CPU-z and look at the JEDEC 'SPD' tab of both the Samsung and Qimoda, and set the CAS Timings MANUALLY to match in the BIOS. Problem the Dell's and most OEM PC's severely limit BIOS modifications. At minimum you need to manually set the (CAS-TRCD-TRP-TRAS) e.g. 8-8-8-24 timings.

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

  7. +1 jaquith
  8. jaquith said:
    Problem, you are Mix-Matching RAM in the same primary channel. Best solution get a third stick of (2gb qimoda). The BIOS is reading the miss-matched JEDEC and shutting-down the 'odd' stick.

    (2gb samsung)+(2gb qimoda)+(2gb qimoda)

    Solutions:
    1. Replace the Samsung with a stick of '(2gb qimoda)'.
    2. Use CPU-z and look at the JEDEC 'SPD' tab of both the Samsung and Qimoda, and set the CAS Timings MANUALLY to match in the BIOS. Problem the Dell's and most OEM PC's severely limit BIOS modifications. At minimum you need to manually set the (CAS-TRCD-TRP-TRAS) e.g. 8-8-8-24 timings.

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

    http://www.cpuid.com/medias/images/en/softwares-cpuz-05.jpg


    LOOK AT THIS
    http://static.picuna.com/photos/original/25221.jpg
  9. Different IC's - same solution = 1. Replace the Samsung with a stick of '(2gb qimoda)'.

    I have many servers (RDIMM) and workstations (UDIMM) using Xeon + ECC and I have (2) boxes of the SAME ECC RAM, in my case 8GB. I never mix ECC they have different IC's.

    Your MOBO supports only Buffered/Registered aka RDIMM and in PAIRS.

    Further, there are (2) two types 'ECC': 1. Buffered/Registered aka RDIMM and 2. Unbuffered aka UDIMM ECC RAM they can never be mixed - period.
  10. Just looked-up your MOBO, it's Quad Channel. That also means the RAM must be installed in PAIRS. Socket 771

    http://support.dell.com/support/edocs/systems/ws490/en/ug/memory.htm#wp1043338

    "Fully buffered DDR2 memory modules can also be installed in pairs of two; in this case, the computer will continue to operate, but with a slight reduction in performance. The pairs must be matched in size, rank, and organization.

    Install memory modules in order of their labels on the system board; matched sets of four should be installed first into DIMM slots 1-4 and then into DIMM slots 5-8 on the system board. Pairs of memory should be first installed into slots DIMM_1, and DIMM_2, then DIMM_3 and DIMM_4, and so on.

    NOTICE: Do not install non-ECC or unbuffered memory modules. Doing so may cause the computer not to boot."



    Crucial -> http://www.crucial.com/store/listparts.aspx?model=Precision%20WorkStation%20490&Cat=RAM
  11. ^ Just looked-up your MOBO, it's Quad Channel. That also means the RAM must be installed in PAIRS. Socket 771 ; see above.
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