On Sat, 2015-08-22 at 19:08 -0700, walt wrote: > On Sat, 22 Aug 2015 04:08:41 +0200 > <waben...@gmail.com> wrote: > > > I'm using XFCE as DE and xfwm4 as WM. Since I bought a new GPU > > (Radeon > > R7 250), I don't use compositing any more because it causes tearing > > when I watch videos in fullscreen with 3840x2160. With this GPU I > > also had some random freezes when compositing was enabled. > > > > Beside this, performance is very good, regardless compositing is > > enabled or disabled. Scrolling text or moving windows around is a > > bit > > faster and smoother with compositing enabled, especially when other > > windows are in the foreground. > > > > With my old GPU (Radeon HD4550) I always had compositing enabled. > > Everything was smoother and I saw absolutely no glitches, but > > performance was also good with compositing disabled, just not quite > > as smooth as with > > I forgot about xf86-video-ati until you mentioned it, so I just > emerged > it and (I think) made all the changes needed to reconfigure Xorg to > use > it instead of fglrx. > > Maybe I'm just too tired right now to think straight, but the error > messages I see in Xorg.log tell me that my video chip is not > supported. > > But, in the process of switching to xf86-video-ati and then back > again > to fglrx I noticed this error message from xfwm4: > > "Error opening /dev/dri/card0: No such file or directory" > > Correct, I have no /dev/dri directory. Do you have one? > > For radeon (free driver) you need to configure more than Xorg, check wiki article about radeon driver [1], It needs in kernel support, also most cards especially "newer" (>=r600) need proprietary firmware.
[1] https://wiki.gentoo.org/wiki/Radeon
