The eVGA 680i mobo has BIG problems when using 8800 SLI together with ANY kind of sound, no matter which soundcard, even onboard is broken. Totally ear and brain destroying screaching and crackling etc...
But ONLY when using 8800 cards running in SLI mode!

See this threads at eVGAs forum.
http://www.evga.com/community/messag...71&whichpage=1
http://www.evga.com/community/messag...TOPIC_ID=21219
http://www.evga.com/community/messag...TOPIC_ID=21425

The problem is official now, and nvidia is working on this, as stated here by an official eVGA Tech-guy
Quote Originally Posted by EVGATECH_JacobF
Hi,

We have reproduced this issue [8800SLI + broken sound] here, and I can assure you that resolving this is a top priority right now for NVIDIA and EVGA.

Also, speaking on behalf of myself, the Asus Striker, it is the same chipset as the EVGA board, so should suffer this issue, but as I mentioned, we are working very hard to resolve this.

Thanks,
Could you please test whether this bug is alive on the Asus Striker Mainboard as well?

Just plug in any soundcard you want and play some games with 8800 SLI ENABLED. (Gothic3 demo would be perfect).

If there is a major design flaw with all 680i mainboards, the world has to know.