Far Cry

Testing at 2560x1600 does not seem to work right in Far Cry. Both ATI and NVIDIA show severe rendering errors (QuadSLI first, 2nd screenshot is CrossFire).

Elder Scrolls: Oblivion

Benchmarking Oblivion was not possible at this time, because the Quad-SLI system kept crashing after about five seconds of walking in the game.

UPDATE: (May 03)
I just had a phone call with NVIDIA who told me that an updated driver is available that fixes both Far Cry and Oblivion and also a number of other reported display corruption issues.
Unfortunately this driver is not available online, you should talk to the system integrator where you got the QuadSLI system from, they will sure be able to help you.