When I had my old 7800gt running half life 2 and other steam games ran with pretty decent frame-rates. With my new radeon 4870 and fglrx 8.54.3 things arent that smooth. Wine version is 1.1.6.
Initially graphics was messed up, this was solved by adding "dxlevel 81" to hl2 launch parameters in steam. Afterwards everything seems to work ok, but the frame rate is low, about 10-20 fps, running in 1920x1200 or 1024x768 seems to make little difference.
Glxinfo reports that direct-rendering is working.
Native games like Quake4 works fine.
Is it possible to get source-based games running decently with 4870 and fglrx-8.54.3 at the moment?