Power consumption
We're testing just how well the Accelero Xtreme 7970 cools by pitting it in a head-to-head battle against the reference heatsink. It needs to be fundamentally better than the shipping HSF unit for it to be a viable option for enthusiasts.
The test system setup can be found here, and the test methodology is one of using three different presets for idle and load power-draw, temperature and noise tests.
The first graphs in each power, noise and temp series shows performance with the GPU at the default 925MHz core and 5,500MHz memory settings, together with the default GPU voltage of 1.17V. The second graphs show performance once the GPU is overclocked to a healthy 1,100MHz core and 5,800MHz, along with a bump in the core voltage to 1.22V. Lastly, the third series of graphs keeps the overclocked frequencies at 1,100/5,800MHz but increases voltage to 1.25V, really hammering the ability of the coolers to maintain low temperatures and noise.
Ambient temperature for all tests hovered between 23°C and 23.5°C. Let's start off with power-draw.
This graph shows the at-mains power-draw when the system is idling and after running Total War: Shogun 2 for 10 minutes. What's interesting here is that the Xtreme-laden card pulls six fewer watts than the reference heatsink, with all other factors being equal.
Increase the speed and voltage of the card and, obviously, power-draw creeps up. But again, the Xtreme 7970's cooler pulls fewer watts. The difference isn't huge, mind.
High speeds and 1.25V pushes the reference card's system-wide power-draw to 300W on the nose. And yes, the Xtreme manages to shave a few watts off this figure.
What we can say here is that both heatsinks pull, roughly, the same amount of power when idling and under load.
