Here’s the GPU benchmark test for VrayRT:
In there the GTX 480 is just behind the 580 and still much faster than 2xQuadro 4000
I’ve been looking around to see how to fix the heat problem, it seems it’s OK for it to go in to the 80’s but I think that’s just too high, since I’ve got a thing I’d like to maybe set to render overnight I don’t want to be concerned that I could burn out the cards if I’m not there watching it. Looks like the voltage is set higher than necessary and lowering it can improve it. I can also lower the clock speed a bit probably without effecting the speed much.