Graphic cards with no OTES should be banned from SLI rigs ;-) Otherwise you've got overheating problem.. does temperature regard to first card in SLI (in my SLI first card is always hotter 10 degs) ? If so, side fan should help a bit, but it must do exhaust job, not intake. Are you sure your bridge is not overheating, too ? I'd try to maximise all intake fan's speed and minimise all exhaust ones speed, if it fails - change GTXes to OTES ones (or do some WC), with fan regulation (Asus ?). It's not an offence for GB, you can keep GB's motherboard ;-)