talking about dma... udma modes?

Discussion in 'Windows Desktop Systems' started by patheticgeek, Feb 11, 2002.

  1. patheticgeek

    patheticgeek Guest

    although all my drives are running in udma, xp ain't taking them to all their capabilities..

    my hard drives are udma66 compatible, the bios supports it, but xp doesn't go any further than udma mode 0.

    no prob, i haven't got the 80 pin cables, but windows could still go up to udma mode 2 (ata33) with regular 40 pin ones.. funny is, the cd-rom drive is reported by bios as udma33, and xp uses it as a 'udma mode 1' drive, and the disks, reported as udma66, are locked on to mode 0... annoyng, to say the least.. anyone know how to force the faster udma modes?

    (and has anyone got a solution for that irritating sound when playing back mp3's with the audioPCI 128, aka Vibra? no, the drivers don't fix it, pio modes, delay transaction, etc etc.. nothing works.. still trying to set pci latency to 0 through software , since the bios doesn't have it..)

  2. allan

    allan Guest

    To enable udma in xp, follow these directions:


    Add DWord Value , and then add the following registry value:

    Value Name: EnableUDMA66
    Data Type: REG_DWORD
    Value: 1

    Also, you can visit:;EN-US;Q247951
  3. patheticgeek

    patheticgeek Guest

    well... same as nothing...

    i had already came across that article in ms knowledgebase... ignored it because it was directed towards intel chipsets (not my case... VIA), and i wasn't looking for udma66 support, just faster udma33... though it makes sense activating udma66, so windows can then choose the best possible mode.

    tried it, though.. no changes! still udma mode 0 on both hard drives!

    well, thanks anyway! all help is apreciated... :)

    best regards


    (btw... already tried via drivers and updates... but that VIA tool didn't seem to work..)
  4. mavis

    mavis Guest

    I just posted this for Geezuzz and thought it might help you too...

    check out his thread (geezuzz's) re: DMA problems, I have a link there to the original post I made for another guy a while ago.

  5. patheticgeek

    patheticgeek Guest

    it can't be convinced...

    tried it also, but didn't worked... the problem here is not putting the drives working as udma drives (they already are!), but making xp use them as more than just mode 0 (the slowest udma mode) drives. (the increased speed is great for video editing.. without having to worry about getting expensive scsi disks!)

    will keep searching for a solution...

    again, thanks for the trouble. stay well..

    (and has anyone ever used the cd player in analog mode? it takes an eternity to skip musics!)