i have a new Gigabyte GA-MA78GM-UD2H board with AMD X2 processor
For comparison i installed both ubuntu 9.04 and windows7 on it.
under both os'es i installed the latest 9.6 drivers and took it for a test drive on a large lcd display.
under ubuntu dvd playback was not perfect, now and then i saw horizontal displacements of the screen, a little bit sluggish
then i tried a hd clip and this was worse, very choppy
processor went to 100% on one core
next i booted windows7 and both the dvd fragment and the HD clip played very well, very smooth, processor load about 40%
my question am i doing something wrong or is it normal this board runs better under windows?.
There's no video-decode-acceleration yet in the Catalyst for Linux driver, while it's in the windows one. That's why your hd-clip plays back smooth in Windows but choppy in Ubuntu.
The "horizontal displacements" with your dvd are due to missing vsync support in Catalyst. I don't know if this still applies, but for me (the latest Catalyst that supports my card is 9.3) the only way to get tear-free video is to use opengl as video-output-method and to set sync-to-vblanc to "always on" in the catalyst control center. Note though that this is even more cpu-hungry than the default video-playback-method (Xv) and probably also wont work with desktop-effects.
Edit: If you're an advanced linux-user you can try and built the latest linux-kernel + latest radeon which should give you decent video-playback without tearing and relatively low cpu-usage. But you'd probably still not be able to playback fullhd-videos.
@remcoh : It is but chances are it will be implemented in the open source drivers before ATI has a properly release fglrx version with it.
On a side note ATI is working on the Open Source drivers and those are being coded correctly. The fglrx driver is like hacks on top of the windows drivers to add linux support, and those hacks aren't that great.