Power consumption is very important today, with people more aware of the rising costs of living. Adopting a more efficient computer will reduce the cost across a year. That said, someone running an overclocked, overvolted system will not be that concerned with power consumption.
We used a calibrated meter to measure the power at the wall. No monitors were factored into the readings. All systems included the same graphics card, memory configuration and hard drive population.
We measured wattage at the socket when running Cinebench R11.5 64 bit which loads all cores to 100% utilisation. The graphics card was inactive during the reading.
When overvolted and overclocked to 4.8ghz, the system takes 191 watts at the socket when primed with Cinebench R11.5 64 bit. This is around 20 watts less than the 6 core Core i7 3960k system at reference clock speeds.