"At idle, our system when coupled with the Sapphire Radeon HD 4770 uses around 135 Watts of power, which increases to 170 Watts in a CrossFire configuration, almost identical to the power consumption of a single Radeon HD 4890. During video playback the Radeon HD 4890 actually uses slightly less power than our CrossFire setup, with a single Radeon HD 4770 board consuming a tad under 150 Watts.

Finally, rendering an intensive 3D rendering workload, a single Radeon HD 4770 in league with our Core i7 system uses 185 Watts, which rises to 258 Watts in a CrossFire configuration, less than the Radeon HD 4890's 275 Watt consumption under load."