Actually the primary reason people worry about using rounded cables (and their worries have merrit) is because of the wonderful effect of electromagnets. Any conductive material, while current is passed through it, is an electromagnet. Also, a wire without current which has an electromagnetic current near it will generate a current, albiet quite small. (Ever try running a magnet over a coil of wire hooked to a really sensitive voltmeter?
)
Anywho, as of the UDMA 66 standard, all the IDE cables went from 40 to 80 conductor. Every other wire in an 80 conductor cable is hooked directly to ground. They did this to try and curb the amount of electromagnetic interference from one wire to the next.
The problem is that rounded cables still have all these grounding wires, but they're no longer in any particular order. When all the wires are in a flat cable thus a horizontal line (IE data-ground-data-ground-etc), ideally the majority of the electromagnetic field created by a data wire would be absorbed by the ground wire next to it
before it hit another data wire, thus potentially corrupting data. Rounded cables don't have this nice benefit, and there will be more than a few places in the cable where a data wire is right next to another data wire.
At one point or another, I found an article describing how to kill an IBM hard drive. Rounded cables and removable drive cages were at the top. Despite my searching I couldn't find it, but Lost Circuits partially conferms my suspicions about rounded cables
in this article.
Not that we should all stop using rounded cables in normal operation - the data error rate is a lot higher, but as most of us have found, our hard drives still last pretty long. It is something to consider, especially if you're intending to use a RAID-0 array. As we all know, RAID-0 pretty much the least stable way to run hard disks in the first place, so adding another layer of instabiltiy (rounded cables) on top, however minor it is, may bug some people enough to never use 'em. I do use them, and they've never given me any hassle, but my server has flat cables all the way. Something to ponder.
PS: Stay away from the removable drive racks at all costs ^_^
From Lost Circuits article above
We tested several of these devices with the IBM 60GXP and the unfortunate result was that not a single drive survived in the removable rack for more than a few hours.
