So Sarah was noticing on her new 4-core Xeon system with gobs of this and that that she was getting nasty screen lag and tearing during World of Warcraft, as if her system was pitifully slow. We tried to jack the settings down, but nothing helped.
Well, it took a bit to figure it out, but we found a fix: Jack the settings up. See, her computer/video card are so damn fast that it’s sending frames over the DVI-D connector to her 24" LCD faster than the display can draw them, so it gets overloaded, pauses, and starts over. In short, the problem wasn’t that her computer/video card weren’t fast enough, but that they were too fast. So, enabling all the glitzy full screen antialiasing, 4x multisampling, and all that jazz causes everything to work so much better — no screen tearing and lag. There’s still a little bit, as she’s really pushing the limits of what the screen can do, but now we’re right at the threshold where things look pretty good. I suppose this is a downside of my unfamiliarity with LCDs, as CRTs never had these sorts of problems.
So, anyhow, if your 3D performance sucks on an LCD and you have a wicked-fast box, just keep jacking the settings up until it improves.