5.3 GH/s @ 36 watts + 20 watts for laptop = 10.6 watts/ghps
68 GH/s @ 620 watts = 9.1 watts/ghps
Efficiency: Avalon
That is an unfair comparison. Drive the Single with a 5-10W mini-computer board similar to the TP-LINK in Avalon (instead of a 20W laptop), and the BFL solution becomes more efficient than Avalon.