System Idle: 290 watts
Mining: 925/1375mhz, 1.17v, 630 watts
Mining: 925/340mhz, 1.17v, 625 watts
Mining: 925/340mhz, 880mv, 360 watts
Mining: 925/340mhz, 865mv, 345 watts
~1650mh/s
so correct me if I am wrong, we have to add 290 watts to these figures to get the wall number:
Mining: 925/1375mhz, 1.17v, 630 watts -- 920 watts @w
Mining: 925/340mhz, 1.17v, 625 watts -- 915 watts @w
Mining: 925/340mhz, 880mv, 360 watts -- 650 watts @w
Mining: 925/340mhz, 865mv, 345 watts -- 635watts @w
so, lets take the best case 635watts, 1650Mh. if you had 6 of them in a rig to compare one of my 4X5970 rig
4x5970 2950Mhash at 1250watts
6X7970 3300Mhash at 1270 watts
so, basically you can get 350 more Mhash for another 20 watts.
in conclusion, it beats the 5970, but just barely, and this does not take into account the price of hardware!!
edit: i think I just talked my way out of the newegg cart of 7970's