There's no such thing as an eSATA to USB cable. They are two completely different and incompatible standards. There is an adapter to plug a n eSATA drive into a USB port, but not the other way around. The only other thing they make is called a 'breakout' cable, which is designed for the eSATA/USB combo ports built into newer laptops. The shape of the port allows either a USB or eSATA plug to be inserted, but not at the same time.. The eSATA pins are on the top of the port, and the USB pins are on the bottom. The breakout cable basically just splits the jack so you can use a USB and eSATA device at the same time. The USB and eSATA lines are not connected to each other.