[citation][nom]lucid_lynx_or_GTFO[/nom]Gulli: ATI has done something about Linux drivers, they released documentation to x.org. Try the Ubuntu 10.04 alpha CD, the stock X11 radeon open-source driver runs Compiz better than the ATI proprietary driver, with far better 2d performance(and this on a mobility Radeon 880g IGP).[/citation]
It's not that ATI drivers on Linux don't run stuff, they just perform a lot worse than their counterparts on Windows. I have the latest drivers for my HD 5870, but my screen will go black for a second or two whenever I open a video and when playing the video the rest of the system is noticeably slower than on Windows, even adjusting the volume sometimes causes hickups. My cpu is a core i7 920, so ATI has absolutely no excuse for this poor performance, especially since Nvidia cards don't have these problems on Linux. But as I said, if you're not on Linux, ATI rules (my HD 5870 eats Crysis for breakfast on Windows and ATI offers more bang for buck at every pricepoint).