bhoar

An eSATA/USB (akas eSATA combo) port gives all of the features/speed/etc. of eSATA, but you also get the bonus of device power as well. If I had the choice, I'd rather connect an external drive to eSATA instead of USB 2.0 for performance reasons. If the drive is in a standard eSATA enclosure and has it's own power, you can use a standard eSATA cable to connect to the eSATA/USB (aka eSATA combo) port. It works just like a standard eSATA port.

With the right cable and/or enclosure, an eSATA/USB port also provides power to the eSATA device attached. Standard eSATA does not provide power. All laptops with the combo port provide 5V power and almost all desktops with the combo port provide both 5V and 12V power. Plus, you can also use the port as a USB 2.0 port when not using it for eSATA connections.