Sorry ..but I don't consider Tom an authority on this and besides he has a
reputation for taking a long time to update his pages....probably because
he is too busy being a physician. However from what I read scanning the
first page he is saying to use different  channels or controllers for your
devices which is a completely different thing from what you wrote and
always a good idea. Two hard drive controllers can access the devices
simultaneously. But If I am not mistaken we are discussing using a new hard
drive ...for example Ultra 2 with a old CD ROM Mode 0 on the same channel
and your saying this results in a performance loss. At least that is how I
read your first statement.

<Another reason why you would want to do that is the IDE
<channels only operate as fast as the slowest device on that
<channel

In the last six years this statement comes up from time to time on PCBUILD
and is an old idea that despite huge changes in IDE hard drive and
controller technology still hangs on. Modern controllers can handle two
devices on the same channel without a degradation in performance.  I am
running a Mode 4 EIDE hard drive with a Mode 0 4 speed CD ROM on the same
channel of a Tyan Tomcat III board....there is NO degradation is
performance.  I am running this machine with a high end ULTRA hard drive as
a master with a very old AT mode 1 drive as a slave ...there is no loss of
performance.

  For a better authority try reading your motherboard manual. My FIC PA2007
manual circa 97..and my Tomcat III circa 96  specifically discuss this
issue and clearly state that you can mix device modes without
concern...BUT  they also recommend putting devices on different channel
when possible..they probably wrote these pages precisely because this
idea  of performance loss from mixing IDE modes on the same channel won't
go away

m



>http://www.tomshardware.com/guides/storage/hdd-01.html
>
>for a small explanation of why you still would want them on
>seperate channels.(I mean a slow device and a fast device)
>"...On one EIDE channel, the 2 devices have to take turns
>controlling the bus. If there is a harddisk and a CD-ROM on the
>same channel, the harddisk has to wait until a request to the CD-
>ROM has finished. Because CD-ROM's are relatively slow, there is
>a degradation of performance. That's why everbody tells you to
>connect the CD-ROM to the secondary channel and your harddisk
>to the primary. The primary and secondary channels work more or
>less independently of one another (it's a matter of   the EIDE
>controller chip). "...
>Dale Laluk / [log in to unmask]

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