I've been running my setup for about 3 weeks now as is, and for a few weeks prior with a different psu and only one graphics card
My current setup is
i7 2600k @ 4.6ghz
Asus maximus extreme-z mobo
GTX 580 SLI
Corsair 1050HX psu
Now normally both cards are within 1-2 degree's of each other, I monitor them frequently in MSI Afterburner. idle they sit between 35-37 degrees and under load, in something like Battlefield 3 on Ultra they both sit between 60-63 degrees.
Now for whatever reason my GPU 1 idle is now sitting 10 degrees hotter than normal at 45 while GPU 2 is normal at about 36. I'm really puzzled as to what could be causing this, was debating swapping there spots, but I'm not sure that would solve anything. I opened my case and from what I can tell everything is working fine.
Is it possible that one of the fans is crapping out and not running as efficiently? I have the Gigabyte GTX 580's.