Altho its possible to have 40c on all these cards with watercooling, but that means his ambient temp would be damn low. I highly doubt he can save much more than 10w.
You're pretty dense.
Just look at the bottom graph on this page.
http://www.silentpcreview.com/article1103-page5.htmlThey went from 415 watts to 386 watts, 29 watt decrease on a single 5870 by lowering the temps. That was also only a 21c temp decrease. I will be gaining at least a 40c decrease in temps. I did with my 6970's under water and saw a large decrease in power draw, and the same should be exaggerated even more on a 28nm card. BTW, No, my ambient temp stays around 72F. I just have a lot of radiator.