Artifacts with 7800 GTXs in SLi

[Captain Kirk]

So this is weird. When my system is in SLi mode, I'll see red or white specks (snow artifacts) in games like Doom 3 and CS:S. Checking the temps, both GPUs are close to 70C, but stay near 66C. They run at about 58C idle. Now here's the odd part. Turning off SLi, there are no more artifacts. Yet the temps on the primary GPU are still reaching that high 70C area.

So what do you folks think? Lack of cooling? SLi being funky? The cards aren't overclocked, aside from the stock BFG OC clock.

 

[Zinn]

I had artifacts with my 7800 GTs... then I tried swapping them into alternate slots, and they went away. Give that a shot!

 

[roflcopter]

I have the same problem. In single mode I can overclock my card tot 490/1400 without artifacts, in SLI mode it starts artifacting at 475/1400. I think the lower card is heating up the top card.