Fastest external self-powered?

[Mercutio]

Nice easy question. What's the quickest self-powered external? Would be looking in the 300-500GB range.

Edit: I kinda implied it by self powered (esata tend to want a USB power plug at least) but USB based please

 

[Mercutio]

For what speed drive? As far as I know USB can only really power 5400rpm 2.5" or smaller and probably SSD's?

 

[Mercutio]

Was generally looking at the WD passport or the freecom XXS but I guess caddy+drive could be an option.