We performed our power consumption measurements using an Extech Power Analyzer 380803. This device is connected before the PSU and measures the power draw of the entire system (without the monitor), including the power loss that occurs in the PSU itself. In the idle mode we start the system up and wait until it stops accessing the hard disk. Then we use LinX to load the CPU. For a more illustrative picture there are graphs that show how the computer’s power consumption grows up depending on the number of active execution threads in LinX. The mainboards are sorted in alphabetical order on the diagrams.
Alas, the Maximus IV Extreme needs a lot of power to run in the default mode. It is not because ASUS mainboards generally have somewhat higher power draw compared to others and not because this one has an Nvidia NF200 controller. The controller does contribute to the mainboard's overall power consumption but it does so in every mode whereas we only see a big difference from the other mainboards at maximum load. This may be due to the mainboard's not working correctly in its default mode. As you can see in the next diagram, which shows the power consumption data for the same mainboards in overclocked mode, the Maximus IV Extreme doesn't differ from the others then, and the small difference can indeed be attributed to the additional Nvidia NF200 controller.