Well, I have noticed that my newer Gigabyte card runs slightly cooler than the older one. About 2C cooler on load (testing with 3DMark 11 and Heaven). That could be due to airflow as well. Not sure if it's ASIC quality or not. I'll try OC'ing the cards further than their current speeds. But ambients are ridiculous right now in Malaysia at around 30C leaving my case temps around 38C and I can't push the cards too much until I get an A/C for the room with the rig.