Guys, I've been reading about all sorts of mods but so far none appears capable of beating my results:

Sapphire 480 Nitro+ 4GB
Stock ROM, undervolted
21~22MHs - 48 watt...
That's something like 2,3 W/MHs, no heat, no fan noise...

Cool, right?

48watt on GPUZ, how about from the wall?
nevertheless, impressive for a single GPU miner.
why do you turn off GPU 2?