Mike Walsh wrote:
On older motherboards the I/O speed will be the protocol of the
slower device; PIO mode is worst case. This was usually a problem
with a hard drive and a CDROM on the same cable. Some say that newer
boards with dual fifo can run different protocol for each device. I
have not tried any tests to verify this.

*I* have. Pretty much any board made after around 1994 will run each drive
at or close to it's rated speed (or the rated speed of the IDE channel,
whichever is greater) regardless of whatever else is on the channel.

I just published the results of a test I did to prove this in this NG about
six or so weeks ago.
--
~misfit~

Steve James wrote:

Hi

I have two HD's on the same IDE channel, I think one is faster than
the other (ATA and RPM), will the fastest one be 'held back' by the
slowest one or not ? I have my O/S and program files on the main
(fastest) drive and only use the slower one for storage and the
pagefile. (to reduce head travel)

MTIA

Steve