P4P800 D CD-ROM won't use DMA mode

  • Thread starter Thread starter Darkfalz
  • Start date Start date
D

Darkfalz

This is under XP, my CD-ROM which supports Multi Word DMA 2 (according to
BIOS) refuses to use anything but PIO Only under XP.

This same CD-ROM with my last system (P3V4X) worked with DMA fine under XP.

Any help?
 
"Darkfalz" said:
This is under XP, my CD-ROM which supports Multi Word DMA 2 (according to
BIOS) refuses to use anything but PIO Only under XP.

This same CD-ROM with my last system (P3V4X) worked with DMA fine under XP.

Any help?
Click to expand...

There was a posting about this a while ago. If transfer errors are detected
on an IDE cable, the driver can shift down the transfer rate as it pleases.
A search in Google dug up a couple of links.

http://www.gmayor.dsl.pipex.com/cd_writer_udma_mode.htm
http://www.microsoft.com/whdc/hwdev/tech/storage/IDE-DMA.mspx

Are you using the 40pin/80wire cable (thin wires versus the fatter
ones on the 40pin/40wire old style cable) ? Higher transfer rates
need the 80 wire cable, as 40 of the wires are ground signals that
improve signal transmission.

HTH,
Paul
 
Are you using the 40pin/80wire cable (thin wires versus the fatter
ones on the 40pin/40wire old style cable) ? Higher transfer rates
need the 80 wire cable, as 40 of the wires are ground signals that
improve signal transmission.
Click to expand...

I'm using a 40 pin cable of course, because it's not an UDMA device.
 
It seems like in some cases, when reading a badly burned/made disc, that the
drive takes too long to respond while trying to correct the errors, and
Windows decides that "The device failed to respond within the timeout
period" (as shown in Event Viewer). If that happens enough, Windows will
drop the UDMA mode or switch to PIO entirely.
 
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