To test power consumption today we are using a Keithley Integra unit and we measure power consumption from the VGA card inputs, not the system wide drain. The best way to get maximum load results is by using Furmark, and even though it is not indicative of a real world situation it shows the limits the card can theoretically demand. The ‘gaming’ results are measured when playing Crysis Warhead and is a more valuable result to take from this.
We were impressed to see the card only consuming 13 watts of power when idle and a modest 52 watts when gaming. This is a very efficient board design which offers low power drain combined with excellent gaming performance. Obviously when adding two cards this power consumption doubles. Gaming and Furmark results aren't exactly 200%, falling slightly shy of each figure by a few watts.