On 19 Mar 98 at 21:22, Lindstrom, Rick wrote:

> The builder slaved the CD-ROM drive to the hard drive, with both
> on the primary IDE port on the MOBO. Besides the fact that this
> will make it difficult to add another drive at a later time, my
> understanding is that doing it this way will compromise the
> performance of the HD. Something about the IDE port being no faster
> than the slowest device attached to it, which in this case is the
> CD-ROM drive.

  IDE/EIDE devices run the channel in various "PIO modes".
Traditionally, the channel would only run at the fastest mode
supported by both devices, and (also traditionally), CD-ROM drives
didn't support much more than mode 1.
  Both of these traditions seem to have faded over time.  Modern
CD-ROMS support higher PIO modes, and it appears that some modern
chipsets -- this may be tied to UDMA support -- can switch mode
depending on which device is being addressed.
  So if this is a new machine (430TX, 440LX?, VP3?), this is probably
not an issue.  If it's an older machine AND an older CD-ROM drive,
this might be a concern.

David G