Yep. Ive been trying to say this all along as i had the same problem with 2 mobos running 2 5850s with twin tubo pro's mounted till someone said i was totally wrong. top card will get really hot. i had a 120mm 1200rpm fan attatched next to the cards and the top 5850 still reached 80'c+ though im not too sure it would drop the temps that dramatically if the side panel fan was acting as an exhaust instead. IMO top card will still run hot reguardless of this unless you get one of the more expensive boards that support tri-fire. so you can have a bigger gap between the 2 cards.