2 watts a hash with good psu is spot on…   by good psu I mean  plat or some gold psu's


so 400 watts at 200gh

380 watts at 190gh

360 watts at 180gh

300 watts at 150gh


all gh was done by freq change.

if you do the pencil mods and underclock you can get lower then 2 watts a hash.

I have 420gh at 560 watts  

 3 s-1's underclocked and undervolted  

 so I get 1.33 watts a hash.