For my power testing comparisons, we looked at both discrete and integrated graphics solutions.
Discrete Power Consumption
Integrated Power Consumption
Here we can see that the Intel G965 chipset on the Asus P5B-VM motherboard uses quite a bit more power when in idle mode with both discrete and integrated graphics options. However, once the system is at full load, the Core 2 Duo E6400 and G965 uses just a few watts less than the Athlon X2 5200+ on the AMD 690.