I don't know what is going on. Must be something I'm doing. mac pro 2.66 with x1900 512mb plus 4gb ram. I am running quake 4 at ultra with no aa on 1920 x 1400? on a 30ACD. It runs fine for a couple of min.. then it begins to crawl.. so bad I cant move, one frame at a time. I though this setup would run an older game like q4 at max resolution.. NO? Is this normal for a mac pro? P.S Q4 is updated to the latest version.