Comment: If you have the choice go eSATAp (eSATA + USB) instead of eSATA (non self powered).
eSATA on Apple IMac!
http://blog.macsales.com/6374-owc-offers-first-ever-esata-interface-for-imac
eSATA used for Final Cut & ...
What is eSATAp?
eSATAp is a high speed time saving connection for external storage.
It is 3X faster and compatible with USB. As fast as USB 3.0 and Firewire 800.
eSATAp ...