2nd graphics card is running hot while the other is fairly cool?

[Corpsecrank]

you could crank up the fan on the hot card.

try this |MG| EVGA Precision 2.0.1 Download

Exactly what I was going to recommend myself. Either crank the fan up or exchange the card locations and see if the card runs hot when you swap it for the top slot.

Can you check the load balance on those cards? If the second card is under a heavy load while the first card is not you could have your answer.

What exactly is hot? To the touch or gauged by an application that displays the actual temp.

And I highly doubt the power supply or slot are causing this issue. More likely you need better cooling by adjusting the fan or changing the card locations to make air flow better.