I could never get my top 780 to go below 80c when maxing both cards out. I have amazing airflow too. The heat dumping in the case builds up pretty fast and the top card, as already said, sucks up hot air from the lower card. I sent back on card and will stick with a single 780 until the next round of cards come out. I probably won't ever buy a card that dumps inside the case again. I like to upgrade to SLI eventually. For SLI, you might as well go with blower style cards. Blower style cards will get up to about the same temp in SLI, but won't dump heat into the case.