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 that it tests the complete system (minus LCD monitor, which is plugged directly into an AC wall socket).
The power consumption was not bad on the 870 Extreme3; one of the things that was very nice was that the power draw difference between stock and overclocked was almost nothing. Granted, our overclock was not a big one.
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.
Heat was also not an issue we the temperatures were very close between stock and overclocked as well as idle and load.