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. We measure results while gaming in Crysis Warhead and record the results.
The KFA2 GeForce GTX 580 Anarchy Edition consumes 22 watts when idling. When gaming this rises to 235 watts, which isn’t too bad considering the frame rate power of the solution.
Above is the total system drain at the socket when running the last test in 3DMark 11. 762Watts is a heck of a power drain and is the only downside of creating such a powerful gaming system.