We are now able to find out what kind of power is being used by our test system and the associated graphics cards installed. Keep in mind; this tests the complete system (minus LCD monitor, which is plugged directly into an AC wall socket).
Looks like the small size of the H55N-USB3 helps it to draw less power. Even while overclocked it draws much less than the full-sized boards since there is less to power on this board.
As a new measure, we are now monitoring the heat generation from the key components on the motherboard; this being the Northbridge, Southbridge (if it contains one) as well as the Mosfets around the CPU. The results are recorded at idle and load during the power consumption tests.
Here, the small size of the H55N-USB3 works against it. The small area means smaller cooling on the chipset. There is also much less chance of getting air around the chipset.