To test power consumption, we monitor the overall power of the system through a plug-in electricity usage monitor at an idle and load state. This allows us to show the fluctuation between how much power draw the graphics card takes at idle and at load. By monitoring the overall usage of the whole system, it gives an easy comparison if you wish to do the same yourself as opposed to buying very expensive individual testing equipment.
Surprisingly, over Titan the 780 does have a slightly higher power consumption at full load, with a total system power draw that is 28W higher. Idle power consumption remains the same at 127W showing the cards can still go into a near 0W consumption.