I agree about Tom's pages. They are getting so dated that
sometimes it I consider it a historical site and not a up to date site.
Basically though I think we agree that if there is two dramatically
different speed devices they should be on seperate channels ?

I mean how can there not be a performance hit when you have a
slow CD-Rom on a channel and say your reading from the CD and
at the same time trying to save something from the Network to
your HD. Only one device at a time can use the channel and if the
slow CD is tying things up, the HD will not be as accessable.

Yes you can mix different modes, the newer boards do that well,
but like your manual says, if at all possible split the devices to two
different channels.

Our company sells about 1000 computers a month and do you
think the manufacturers would ship them with the CD-rom on the
secondary and the HD on the Primary controller if they could get
away with both on the same ? It would save one whole ribbon
cable. (Given how cheap the manufacturers are this is a big deal to
them. I mean look at Winmodems and the stupid cheap fans they
have forced on us over the years, all in the name of saving a few
pennies).

> 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


Dale Laluk / [log in to unmask]
P.O. Box 308
Hudson's Hope, B.C. V0C 1V0
250-783-9921

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