I have an Radeon HD 4870 video card, and I have just update to Ubuntu 11.04. Before I was using radeon free video driver, and all hardware acceleration I used was to watch movies on my TV. My TV is permanently attached to the PC, alongside the monitor. I have configured X to have 2 screens, the main one is the monitor. The second one, the TV, is only used to play movies and such. Free driver sucks at gaming, so I missed (but not that much) being able to play some games in my old installation.
Now that I have updated Ubuntu, free driver still sucks at games, but provided a fluid and awesome desktop performance, with all eye candy and special effects compiz is capable of. On the other hand, video playing performance is worse than before. V-sync no longer works, so there is a constant horizontal tear, and periodically video refresh freezes for half a second, making it extremely annoying to watch a movie with an interruption every few minutes.
So I have tried the proprietary driver. Good game performance, I was able to play Penumbra: Overtrue, Trine, Shadowgrounds, Enenemy Territory: Quake Wars, etc. All cool advanced shaders and special effects works. Including movie playback, no periodical freezes and no horizontal tear due screen refresh gives me perfect movie performance. But desktop sucks. I can not use compiz because it is slow, bumpy and fullscreen does not works. But if I do not use compiz, I can have at most one OpenGL application at a time -- and it mus be fullscreen. I can no longer watch a movie on TV while my mother uses the terminal to surf the net, because everything except the OpenGL application freezes. All worse if the OpenGL application is windowed, it won't display what it is supposed to unless it is bellow another X window, what makes the OpenGL to render over that window, a total mess.
When I bought this card people said: buy Radeon because it will support free drivers. Well, radeon free drivers lacks manpower, OpenGL is incomplete and my card has always been underused. Proprietary drivers sucks. Now I want nVidia, at least they don't lie saying they will be well supported by free software.
I am frustrated. I do not know what to do. Do you have Ubuntu 11.04 with Radeon? Does it work? Do you play? Do you use OpenGL applications? What driver do you use? For now I am using proprietary driver (fglrx), without desktop effects and refraining from using windowed OpenGL applications. Now I am happy applications are not taking advantage of hardware acceleration.