Benchmarks - power-draw
The idle power-draw is excellent. We evaluate it by looking for the at-wall figure when the GPU is simply displaying the desktop screen. It's worth repeating that this isn't the ZeroCore power figure, where the Radeon HD 7970 switches off almost completely.
Under-load figures are roughly consistent with what AMD claims, coming in comfortably below a GeForce GTX 580 from NVIDIA. Good engineering, AMD.
ZeroCore usage
Radeon HD 7970's fan does indeed switch off once the operating system is instructed to turn off the display after a set number of minutes. Power-draw drops from 42W to 28W, which is all good, but it seems as if the switch-off threshold is somewhat arbitrary. Sometimes it'll remain off in the long idle state, other times it'll come back on at a very low RPM.
We found it difficult to engineer a situation where it would remain off when downloading files. While obviously a good idea on paper and demonstrable in a system, we'll be doing more investigation into ZeroCore in the New Year.
