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; it tests the complete system (minus LCD monitor, which is plugged directly into an AC wall socket).
There are a few important notes to remember though; while our maximum power is taken in 3DMark06 at the same exact point, we have seen in particular tests the power being drawn as much as 10% more. We test at the exact same stage every time; therefore tests should be very consistent and accurate.
The other thing to remember is that our test system is bare minimum - only a 7,200RPM SATA-II single hard drive is used without CD-ROM or many cooling fans.
So while the system might draw 400 watts in our test system, placing it into your own PC with a number of other items, the draw is going to be higher.
Moving into power usage, we see the ASUS 780G board using quite a bit less power with the IGP enabled over that of the 750a based; this could be due to the fact that it's a Micro ATX board with less features, or simply it could be due to the power usage of the 780G chipset being more efficient than the 750a. With the IGPs disabled and the 9800GX2 working we see that the power usage at idle and load increases quite a bit, due to two graphics cards working.
As a new measure, we are now monitoring the heat generation from the key components on the motherboards, 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.
The 780G based ASUS board produces less heat than the 750a chipset, supporting the fact that the 750a chews more power than the AMD 780G does.