With both the Radeon X1800XL and X1950PRO the Linux binary driver had caused the frame-rate performance to be sliced in half when compared to the Windows Catalyst driver. The only benchmark that didn't see about a 50% drop in performance was Enemy Territory, which is CPU bound being based upon the Quake 3 engine. While the fglrx driver has its share of performance problems right now its image quality between Microsoft Windows and Ubuntu Linux are comparable and the Linux driver contains a number of similar features to the Windows Catalyst suite. Once AMD introduces their new OpenGL driver later in the year the performance problems will hopefully be a thing of the past.
You can read other Linux graphics articles here at Phoronix and discuss this comparison in the Phoronix Forums. Additional ATI/AMD Linux graphics articles will be published later in the week. We wish all of our American readers an excellent Memorial Day.