Ok, I have a problem with SLI on my ASROCK x58 extreme motherboard, when I attempt to run with SLI enabled, my system freezes up about 10-15 min after booting up. When it locks up, I am unable to do anything, I cannot move the mouse, the sound is not looping, it looks like a screenshot of whatever I was doing. I have tried changing my RAM timings, and know for a fact my hard drive is working properly. (I installed windows on it on a separate computer without a hitch.) However, when if I run in a single card setup, the system runs perfect. It is only when I have SLI running does the computer lock up.
I have also noticed that when I start a game, or anything that raises the GPU's temperature, the lockup shortly follows after the fan speed surpasses 85%. The system still locks up at an idle, but it seems increasing the load on the GPU just shortens the time to a lockup.
ASROCK X58 Extreme
2 EVGA GTS 250 512mb
Intel core i7-920
4GB DDR3 1600 Corsair Dominator
750gb WD Caviar Green at 7200
Rosewill Xtreme 850w continuous
One more note, when I unboxed the motherboard the northbridge heatsink had a damaged pin to hold it down. I found one off an old northbridge cooler and the two looked identical.
It sounds to me like a PSU problem. You can check your NB temp in the BIOS, it would shutdown if it over temp.
After reading what you posted I noticed that the both 6 pin connectors were 12v2, I swapped and put one 12v1 and one 12v2 on the cards. The system was stable longer, however ultimately it did crash. I am with you in thinking that it is the power supply, only that it is brand new.(yeah, I do realize they can come with malfunctions.) Is there any way to pinpoint that it is the PSU?
It could be that your PSU is simply defective. PSUs do come with defects at times, and of course cheaper units, like those from Rosewill, have them more often than units from the likes of Antec or FSP.