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  • AHA-2940 @ 112FSB

    Hi all,
    I'm occing a 300A to 504@112. Except from disabling UDMA, all flags are set to "fastest". Everything runs for hours (GFX, ISA-sound etc.) without even getting hot (3-fan sandwich).
    Aany ideas how to get an Adaptec 2940 running at an FSB of 112MHz? I use to get deadlocks when copying big files between scsi drives, i.e. the mouse still moves, but nothing on screen moves or reacts. Does the increased busfreaquency affect the transfers between HD and controller or only between controller and PCI? In the first case I could try shorter cables for the ext. drive.

    Please, I'm not willing to trash all my scsi for 5 more fps ;-)

    Bye,
    SeMudl


  • #2
    I have tried overclocking with an Adaptec AHA-2940 U2W, but to no avail. I was able to get it to o/c at 103 MHz, but nothing beyond. I guess SCSI cards are just too sensitive to the bus speed to operate above 33 MHz.

    Jammrock
    “Inside every sane person there’s a madman struggling to get out”
    –The Light Fantastic, Terry Pratchett

    Comment


    • #3
      Hi Jammrock,

      what about the ASUS P2BS/DS which have "half" a 3940U2W on board, they run perfectly
      at 83FSB. Or is it connected to some unocced part of the BX (maybe technically b.shit, but you know what I mean ;-)?
      I won't swap boards just for that matter knowing that until next christmas the P2B is too slow for my next CPU :-)

      Bye,
      Hellmut

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      • #4
        The chip they use in the P2B-DS is different than the one they use in the AHA-2940. It is designed for operating at the varying motherboard speeds (or so I would assume they would have to do to make it integrated), while the AHA-2940's only needs to be designed to operate the 33 MHz spec. Just a BS guess, but I do know that the actual chips are different (AHA and AIC).

        Jammrock
        “Inside every sane person there’s a madman struggling to get out”
        –The Light Fantastic, Terry Pratchett

        Comment


        • #5
          Hi guys!

          I've got a few comments from personal experiences on the subject!

          1. I used to have an Adaptec 2940AU (pci) card, which ran fine at 75 MHz FSB, on an ASUS TX97 board. This was 37.5 MHz PCI-frequency. It ran perfectly fine for over a year.

          2. I now have the ASUS P2B-S board (1 year old), and I'm running the FSB at 112 MHz, meaning the PCI is running at 37 MHz. This has also worked for a year now, trouble-free!

          3. Any probs. running at higher FSB is related to the PCI-bus, as the HDD isn't using the bus-freq. to anything - opposite with IDE-drives!

          4. The onboard SCSI-controller (chip) on the ASUS board is EXACTLY the same controller as on the Adaptec AHA-29XX Ultra2-series boards. Jammrock, the "AHA" is the model/name of the card and "AIC" is the model/name of the actual controller. The ASUS mobo and the Adaptec AHA-2940U2 BOTH have the AIC-7890 controller!!!

          5. Nope Hellmut, an ASUS P2B-board WILL be able to run the CPU's coming far into the next couple of years. The base model P2B is able to run with any PII or PIII or Celeron! It can up to 150 MHz FSB and it has a multiplier going to X8. This means it can in theory go up to 1200 MHz CPU-speed. This is for the time being. ASUS is VERY good at upgrading older products to support new hardware!

          Cheers!

          ------------------
          HBS - ASUS P2B-S, PII 350MHz(o/c to 392MHz), Mill. G200, 128MB RAM, Cheetah 9.1GB, Plextor 32x CD-Rom, Sony CD-R, Canon Scanner - all SCSI.




          ASUS P2B-S, PIII-550 (o/c to 565MHz), 512MB RAM, Seagate X15 & Cheetah XL, Matrox Mill. G200SG, SB LivePlayer, Plextor 32x CD-Rom, PlexWriter PX-R820T CD-R, Canon BJC-7000 InkJet, OkiPage 4W Laser and Canon CanoScan 300 Scanner.

          Comment


          • #6
            Just my 0.02 worth.

            I have an AHA 2940U which performed admirably at 37.5 MHz on an Asus TX97.

            Moved to a P5A and could never get anything over 105 MHZ fsb to work.

            Moved to a BH6, works fine at 103MHz, with much tweaking will run at 112 MHz for a while. But when run at 83MHz can trash a disk just by running the timedemo in QII !

            So I agree that the AIC chips are very bus speed sensitive, but it would seem to depend also on the chipset/mb combo.

            Cheers
            Clive
            XP 2100+ on A7V8X. G550 DH, 2*60Gb, 512Mb

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