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georgep23

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IDE cable lengths

Whats the safest length of cable I can use to connect an IDE drive to the motherboard.

reasoning:
With the advent of the new fast Ultra IDE drives and the IDE promise raid controller, you can now get 48GB for about £900 ($500) - to act as one drive! (great for video)

I want to connect 4*12gb drives to the controller, but in an external drive case, therefore the cable(s) will need to longer than the average IDE cable - is this possible???
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second

If you put the external drive case right next to the computer there will be no problems.
And if you look more extensive you can found a 4x IDE chanel controller wich will allow you to put 7x16G (the max size Ultra IDE drive - IBM) = 112GB and in the 8th put one ATAPI CD-RW (HP 8080i)
I don't think second answered your question.  The IDE specification calls for a MAXIMUM end-to-end length of an IDE cable of 18 inches.  There can be no more than 3 connectors on the cable.  I've built longer cables myself for big cases and have never had a problem, but, the spec says 18".
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ASKER

Yes but what is the max length of the cable? I know there is a limit before data is lost.

As for the 4 chanel controller, is this any good as a Video AV drive (RAID Level 0: can the drives be configured to act as one with no redundancy)?
jhance,
can you repost your comment as an answer?

Also, how long have you made a cable? What happens if the cable is too long, does the drive just stop working?
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theh95

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I'd like to but it seems that theh95 can't read (or understand the IDE spec!).
BTW, here is the reference to the IDE (i.e. ATA) specification.  In it, you'll find the requirements for the cable length in section 4.2:

ftp://fission.dt.wdc.com/pub/standards/ata/ata-3/ata3-r6.doc

To quote:

4.2 I/O Cable

The cable specification affects system integrity and the maximum length that can be supported in any application.

Cable total length shall not exceed  0,46 m (18 in).

Cable capacitance shall not exceed 35 pf.

GEORGE,

HOW COULD YOU ACCEPT THIS INCORRECT ANSWER!!!!!  Post a comment to LINDA in the Experts Exchange area and get her to unanswer this question.  theh95 is WRONG!!!!!
sorry, i accepted the wrong answer.

i will post a comment as you say,

oops.
Once a question has been graded and moved to the previously asked questions, I cannot change who is awarded the points.

Look for a new question posted in this topic area to award jhance points for his participation.

Linda Gardner
Customer Service @ Experts Exchange
Sorry I don't know exact shop/manufacturer/etc. of 4 chanel controllers :(((
Actually the optimal distance is 18 inches. Anything longer than this and there is the potential for lost data. It's possible to use a 5 foot length, but I don't know about the reliabilty. With mission critical data, I wouldn't take the chance.