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.
In such an energy aware climate, AMD are making a big deal out of their new ‘ZeroCore Power’ technology. Many solutions today use power gating, clock gating and memory compression to reduce idle power requirements, but ZeroCore power technology can completely power down the core GPU while the rest of the system remains active.
As with the other 7000 series cards, power efficiency is very good. Tthe HD7850 consuming around 110 watts when gaming. The HD7870 demands around 35 watts more when loaded, averaging 145.