PA-2013 Bios settings for Crucial 256MB 133Mhz CL2

Discussion in 'FIC' started by Gibby, Dec 2, 2003.

  1. Gibby

    Gibby Guest

    I was sucessessfully running three (3) Crucial 256MB, 168 Dimm, Sdram
    PC133, 32Meg x 64, Unbuffered, Non-parity, 7.5ns, 3,3V, CL=3 sticks in
    my FIC PA=2013 Rev. 2 E-O036, K6=3/450, MB. I purchased the same as
    above, but CL=2, and I can only get two sticks in the first two slots
    to run successfully. I have tried all 3 sticks in the first two slots
    and system runs fine. But when I try putting the 3 sticks (Crucial#
    CT32M64S4D7E.16LT )in together (in all 3 slots), I either don't get a
    good memory count, or if it does (just once) I can't get the complete
    Bios bootup (it stops) - I don't get to where it searches HD for
    Windows 98SE. Question: Why will 3 CL=3's work and not 3 CL=2's (only
    two will work at one time)? Perhaps my BIOS memory settings are wrong
    for CL=2. But why do two work but not three?
    Thanks for any help. Gibby
     
    Gibby, Dec 2, 2003
    #1
    1. Advertisements

  2. Timing is tighter for CL=2. There's probably too much capacitance
    in the circuit board traces and the signal rise times get sloppy with
    three sticks just because there are more traces to drive.
     
    L David Matheny, Dec 2, 2003
    #2
    1. Advertisements

  3. Gibby

    Kyle Brant Guest

    | > I was sucessessfully running three (3) Crucial 256MB, 168 Dimm,
    Sdram
    | > PC133, 32Meg x 64, Unbuffered, Non-parity, 7.5ns, 3,3V, CL=3
    sticks
    | > in my FIC PA=2013 Rev. 2 E-O036, K6=3/450, MB. I purchased the
    | > same as above, but CL=2, and I can only get two sticks in the
    first two
    | > slots to run successfully. I have tried all 3 sticks in the first
    two slots
    | > and system runs fine. But when I try putting the 3 sticks
    (Crucial#
    | > CT32M64S4D7E.16LT )in together (in all 3 slots), I either don't
    get a
    | > good memory count, or if it does (just once) I can't get the
    complete
    | > Bios bootup (it stops) - I don't get to where it searches HD for
    | > Windows 98SE. Question: Why will 3 CL=3's work and not 3 CL=2's
    | > (only two will work at one time)? Perhaps my BIOS memory settings
    | > are wrong for CL=2. But why do two work but not three?
    | > Thanks for any help. Gibby
    | >
    | Timing is tighter for CL=2. There's probably too much capacitance
    | in the circuit board traces and the signal rise times get sloppy
    with
    | three sticks just because there are more traces to drive.
    |


    I think you are warm with this analysis. It might be better said that
    the sdram device output loading on the memory interface and sdram
    circuits is higher with 3 versus 2 unbuffered output sdram sticks.
    The capacitance loading is probably substantially the same, as the
    capacitance (residual) is attributable to the mobo runners or traces
    layout. All of the mobo memory traces get driven no matter how many
    sticks you are using.
     
    Kyle Brant, Dec 2, 2003
    #3
  4. Yes, it's overall loading on the memory interface drive circuitry
    that causes the timing problems, but surely the SDRAM circuit
    board traces have some capacitance, too.
     
    L David Matheny, Dec 2, 2003
    #4
  5. Gibby

    Den Guest

    Can I take from this thread that CL=3 is recommended if using all
    three slots, (3x256) and would using even one stick of CL=2 be a
    bad idea on the PA-2013 if filling all slots.

    Den
     
    Den, Dec 10, 2003
    #5
  6. That's how I would take it. CL=2 memory will run just fine at CL=3,
    though, so just set the BIOS to run all the memory at CL=3.

    --Alex
     
    Alex Zorrilla, Dec 11, 2003
    #6
  7. Gibby

    Den Guest

    Thanks will try this if (taps foot while waiting for Crucial to repeat
    their last good offer, but I think I have missed the last boat).

    Den
     
    Den, Dec 12, 2003
    #7
    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.