This is also known as "
Rounding Cables", and I have heard of many cases in which
ATA 66 cables have been rounded. And have seen speed tests showing no drop in speed. Though I'm sure this is not always the case.
When rounding ATA 66 cables, it is much more common to simply
fold them over each other or
roll them up, instead of separating the strands. Not only for preventing
crosstalk, but also so as not to break the
wires inside.
A few companies have caught on to this craze and sell specially made round
IDE cables of all speeds. However, sometimes they make them longer to make up for the bunching up of the cables. Longer than 18 inches, and 18 inches is the maximum length for the
IDE specification.
Personally, I
round my own cables. A 40 strand
ribbon cable costs me about $2, and pre-rounded cable about $20. I don't bother rounding 80 strand cables, I don't feel like taking risks.
I wrap all my rounded cables in green
electrical tape. It matches the
PCB nicely. Now if only I had a
window...