I just bought an Asus USB3 card. If I had bought a very cheap card that goes in an x1 slot, it also needed a power cable. By buying one that goes in an x4 slot, it doesn't need the extra power cable. So sometimes smaller isn't better.
Thanks, I had my computer almost go up in flames because of a bad power supply. Had to build a new one and I have two card that are x1 and one x1 slot, two x16. Has built in USB3 on the back so when more USB3 stuff comes out it should be super fast. I glad you mentioned the powering of the slot. You are very helpful.