For testing power consumption, we took our test system and plugged it
into a Kill-A-Watt power meter. For idle numbers, we allowed the system
to idle on the desktop for 15 minutes and took the reading. For load
numbers we measured the peak wattage used by the system while running
the OpenGL benchmark FurMark 1.9.1 at 640×480 resolution. We also ran the game HAWX 2 and looped the benchmark three times and recorded the highest Wattage seen on the meter.
Power Consumption Results: The XFX Radeon HD 7950 Black Edition is one of the more power efficient cards we have tested. Running the Furmark 1.9.1 Burn it test it pulled 329 Watts at the wall. Under the same circumstances the AMD Radeon HD 7950 with lower clock speeds pulled 330 Watts at the wall. Firing up the HAWX2 benchmark to take a look at our power consumption while gaming the XFX Radeon HD 7950 Black Edition pulled 287 Watts while the AMD Radeon HD 7950 pulled a little less with 283 Watts. The idle power consumption of both Radeon HD 7950’s we sitting pretty below 100 Watts, the XFX Radeon HD 7950 at 98 Watts and the AMD Radeon HD 7950 at 99 Watts.
The AMD Radeon HD 7000 series has a new technology called ZeroCore Power, which shuts down the GPU during periods of long idle (when the screen goes to sleep). When the GPU goes to the power state the fan stops spinning and the GPU core itself consumes 0W while the rest of the PC is still running. This is a really interesting feature and we found that it works great. After the system is at long idle the video card basically shuts down and goes to sleep. With a single AMD Radeon 7950 card in our test system the idle power was down to 86 Watts.
One of the main reasons AMD developed this technology was from feedback from CrossFire users as they didn’t need all those cards running when at idle as they produce noise and heat when it isn’t necessary.