Power consumption and efficiency
The workload for this test is encoding a video with x264, based on a command ripped straight from the x264 benchmark you'll see later. We're tracking power consumption over time in the first set of plots below. The main plot comes from our standard test systems with discrete Radeon graphics. The second one shows system-level power consumption with only the integrated graphics processors in use.
The story of progress from Trinity to Richland is told by comparing the green line on the plot for the A10-5800K with the blue-green line for the A10-6700. The A10-6700 consumes less power during the workload and finishes the job sooner, dropping back to idle before the 5800K does.
The Socket FM2 platform has nice, low power use at idle. The fact that a desktop system based on a full-sized ATX motherboard draws only 23-25W at the wall socket is remarkable.
Despite having a TDP rating of 65W, the A10-6700 system draws 48W more power while executing our test workload than our 55W Core i3-3225 system. In fact, it pulls more juice than a whole collection of configs based on Intel desktop CPUs with TDP ratings of 77W and 84W. At least the 6700 is a bit of an advance over AMD's own A10-5800K.
We can quantify efficiency by looking at the amount of power used, in kilojoules, during the entirety of our test period, when the chips are busy and at idle.
Perhaps our best measure of CPU power efficiency is task energy: the amount of energy used while encoding our video. This measure rewards CPUs for finishing the job sooner, but it doesn't account for power draw at idle.
If you compare the A10-6800K to the 5800K that precedes it, there's only a sliver of difference between Trinity and Richland. Pit the A10-6700 against the 5800K, though, and the progress is a bit more pronounced. We're happy to see the growth, but AMD will need to make much larger strides in order to catch up to Intel.