Thanks guys.... the bottom slot is an option but my case, Antec 1200, and this board (UD7) I guess are not a perfect match... In that the bottom PCI-E slot on the motherboard lines up with the last I/O hole in the case. Therefore with another 580, the bottom portion of the cards I/O shield (the part with the venting) will be blocked due to the lack of another, lower, I/O slot.... I hope that makes sense. I did think about taking a Dremmel to the case and opening it up so that the vent in the card can breathe....