Yeah, when the 1900s, 2900s, and 3870s were out I was using two interconnect cables. Benchmarks, especially 3dmark06 scored much higher with one, and since then I only use one. The 4870X2s only have one interconnect rail on the card, so that supported my thinking. I've noticed that the 5870s have two rails, as do the 4870s. There hasn't been any controversy over it so i'm sure that the 5870s use one interconnect, that is unless more than two cards are used, in which case the 6 rail multi-connector is used. I haven't seen a 3rail single configuration cable, but then again there is prob. one out there.