Power Usage Benchmarks
With the performance story fairly well covered, we turn our attention to evaluating power consumption. The A8-3870K has a 100 W TDP, and the Pentium G620 and Radeon HD 6670 combination is about 131 W combined. Keep in mind the TDP is the maximum rated thermal limit, but it's not necessarily the actual ceiling you'd see running a real world load.
At idle, the stock APU uses less power than our host/graphics processor combo. Additionally, the less-complex Radeon HD 6550D GPU is more energy-friendly under load than the discrete card. Crank up the processor, though, and AMD's four cores consume significantly more power than Intel's two. With both a graphics and host processor load applied, the results are similar.
Overclocking doesn't do AMD's solution any favors. A combination of higher voltage and elevated clock rates push system power consumption up significantly at idle, yes. But the 100+ W jump under a mixed graphics/processing load is particularly disappointing.