I noticed that all of the warm air comes out the front of the card, so I positioned a fan behind the machine to get fresh air flow from behind the open rig.
You mean that you've got a fan blowing fresh air into the exhaust opening on the part of the card with the DVI connectors? I would have guessed that the best performance would come from a fan on the opposite end blowing fresh air over the heatsink and out the back of the case, or one at the exhaust opening drawing the air out of the card. Or both.