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).
One of the advantages of the two-chip solution from Intel is a reduction in power consumption. The Core i5 661 is a 32nm CPU with a 45nm GPU with a TDP of only 87Watts. This reduced power draw helps the Clarkdale/H55 combo to sip power even under full load. The ASRock H55M Pro does quite well even when overclocked. However, adding in extra cards will increase this draw as you would expect.
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.
Here we see something interesting, but not unexpected. The heat produced from the H55 chipset on the H55M Pro is light even when overclocked. However, when you drop in an external GPU the heat increases. Due to the layout of the board, the heatsink gets saturated by the heat of a GPU like the GTX 285.