Power And Efficiency
Our power tests included an idle power measurement where the system was prevented from sleeping (active state), a full CPU load test with multi-threaded Prime 95 (one thread per core), a GPU load test with FurMark’s Stability Test at 1920x1200 and 4x AA, and a combination GPU plus CPU load with one CPU thread devoted to FurMark and the remaining threads devoted to multi-threaded Prime95. Whew!
Two GeForce GTX 480 graphics cards draw way too much power. Need we say more?
Efficiency is a comparison of work done to power used. To calculate that, we first begin with a chart that compares the performance of all real-world (non-synthetic) benchmarks. The cheapest PC is used as a baseline.
Again using the cheapest PC as a baseline, we compare the difference in power consumption to the difference in performance.
While overclocking increases the rate at which a PC finishes any given workload, it also increases power consumption. When performance is increased by a greater amount than power consumption, efficiency is increased. Low-voltage overclocking allows the $400 PC to get the biggest efficiency increase, but it never catches up to the efficiency-leading $1000 system.