On top of that, it might be better sticking to normal ribbon IDE cables rather than cylindrical ones. They might allow better airflow, but apparently there's a lot of crosstalk.
Well, funnily enough, the cable I was using was the cylindrical type. Also funny is that I replaced it with another brand of cylindrical cable. Both were rated for UDMA5 (80 wire). And yeah, the extra wires are ground wires as others have mentioned. It was just a matter of build quality.
- Mike
