GTX570 SLI Performance vs heat and spacing

[Paranoidq]

Hey all,
I was wondering if I could grab some advice. I have one EVGA Classified GTX 570 and I'm looking to grab a second. However I'm aware these cards can get quite hot in SLI and I have some concerns.

The board I have (P8Z68 v-pro) has the 2 primary PCI-E slots right next to each other. A third slot at x4 speed is further away. Would the performance drop off be huge if I put the second card in the x4 slot to save heat, or will the heat be not as badas I'm thinking and I should put it in the higher speed slot?

I have an Antec 902 case (2x large fans at the front, 1x fan on the back and a beefy one on the roof - no fan in the window panel as yet).

Any advice or insight you could provide would be much appreciated.

 

[El Tigre]

I think you should be fine, But I would add a side fan too. Using the PCI-E x4 slot will hurt your performance a bit according to these test runs done by Tom's. It's not too terrible though, if cooling is your concern, the best would be to test it out yourself.

http://forums.anandtech.com/showthread.php?t=2163299

I had an SLI GTX 560 Ti and GTS 450 PhysX setup before my current setup and it was not terrible with heat, none of the GPU's went above 70C during gaming. It may be a little warmer with SLI 570's.