Using Prime95 to place full load on all cores/threads we measured the power consumption of each system. Unsurprisingly, the Celeron G1820 consumed the least amount of power at just 77 watts, followed by the Pentium G3220 with 84 watts and then the Core i3-4350 at 89 watts.
Between the Core i3-4350 and i5-4690K we find the i5-2500K and i5-760, while the Core i7-870 consumes roughly the same amount of power as the i5-4690K.
What's really worth noting is the fact that the Core 2 Duo E6600 consumed virtually the same amount of power as the i7-4790K and 2700K. The Core 2 Quad processors consumed considerably more, reaching a total system consumption of 170 watts.
The consumption trends are much the same when testing with Hybrid when encoding.
We found similar results again when measuring consumption in the 7-zip benchmark.