For testing power consumption, we took our test system and pluggedit into a Seasonic Power Angel. For idle numbers, we allowed the systemto idle on the desktop for 15 minutes and took the reading. For loadnumbers we measured the peak wattage used by the system while runningthe OpenGL benchmark FurMark 1.7.0 at 1920x1200 resolution.
Power Consumption Results: The ATI Radeon HD 5670 512MB and the Sapphire Radeon HD 5670 1GB had exactly the same power draw out of the wall in this test scenario. The idle power scores put the cards at the bottom of the chart for both idle and load power consumption and they only get beat by the NVIDIA GeForce GT 220 and GT 240 graphics cards. The Radeon HD 5670 series is faster than these two cards, so for that extra graphical horse power in the games you will be forced to consume a little extra power. At idle the difference is just a few Watts and that difference is not significant.