To run our temperature tests we allowed the ASUS GTX 570 DirectCU II to idle in our open test bench for 15 minutes at the desktop screen in our office with an ambient of 22.7C (73 degrees F). Then we start a loop of Aliens vs Predator benchmark and record the temperatures. Finally we run FurMark 1.9.1 for 15 minutes and record the temperature to see what happens in a non-real world extreme case.
At idle the card settles in to 32C and the clocks scale way back to conserve power while in 2D mode.
During our gaming loop we saw the temperature hit 54C showing how amazingly well that DirectCU II cooler works. Under 15 minutes of Furmark 1.9.1 the ASUS GTX 570 DirectCU II had a maximum temperature of 69C which is well under the 97C maximum of this FERMI chip. While that is impressive what you need to notice is that this temperature was achieved with the fans only running at 28% for 1410 RPM. Under full load I temporarily stopped all the other fans on our open test bench and the dual fan DirectCU II cooler was hard to hear at full load even with my head only about a meter away. If it is this quiet on an open test bench, then inside of a case it would be dead silent. You could sleep with your head next to this card folding 24/7 and it would not bother you.
We switched the fans from automatic to manual and turned them up to 100% and they are very loud but, wow do they cool well. The maximum temperature went from 68C to 54C with the fans turned up for 14C lower or 21% better cooling which is 1% more than ASUS claims you get with the DirectCU II. Amazing air performance that is getting close to what you would get with water cooling if you can handle the noise.