IIRC Nvidia requires two cards to drive 3 monitors so you'd need SLI for that. To be fair though, IMO you'd want SLI to be doing that a reasonable resolution on a modern game so its not too bad but ...

The two cards were sharing the IRQ long before the problem started, and I would think that if it was a problem, it would crop up when I play games, since games make intense use of the video card and ...