Efficiency Explored: Core i7-980X Versus Core i7-975

Benchmark Results: Power Consumption

The idle power on our system is a bit lower than on the machine Chris used, mainly because of the different motherboard and power supply. Seeing 101W for the quad-core Core i7-975 versus 99W for the new 32nm six-core Core i7-980X is reassuring, though. The new chip has a higher performance potential at lower idle power.

Peak power was 241W for the 45nm quad-core and it doesn’t even get that high with the hexa-core chip, which runs at exactly the same clock speed of 3.33 GHz nominal and 3.46/3.6 GHz in Turbo Mode. How does this translate into total and average power used to complete our benchmark workload?

The total power used for the benchmark workload, including all the software you just found on the performance results page, is significantly lower on the new six-core CPU. That's because the new processor is so much faster that it can go back to idle much earlier. The watt-hours difference equals a 12.4% savings in total power.

Average power is lower, as well. Our measured 134.4W versus 147.5W translates into an 8.9% difference in favor of the new Core i7-980X. Let’s look at how efficiency improves with these savings.