When I switched up to Utopic Unicorn as the upstream basis of my system I got a pleasant surprise: full performance returned in Critter and Scorched3d with the newer DRI3 xserver. A week later performance dropped back to half framerate in Critter. I reverted every package one at a time-hundreds of them-until I found the culprit: libsdl. I rolled it back, full performance returned. A week later another update came out, tested it and it worked fine. This was right in the middle of porting my plymouth theme and multi-encrypted disk unlocker to systemd and dracut, so I was busy and didn't get around to posting this at that time. The bug is squashed, but I figured I should finally get this posted, but here and in my original launchpad bug report:
Today I posted this in https://bugs.launchpad.net/ubuntu/+s.../+bug/1293314:
This bug was finally resolved with updates to sdl, used by all the games I saw it in. When I first changed repos to move to Utopic Unicorn, a new SDL package returned both Critter and Scorched3d to full performance. Then another update reverted some change, and performance fell right back to where it had been. Finally a 3ed update fixed it again, hopefully for good.
libsdl1.2debian_1.2.15-8ubuntu2_amd64.deb brought the original fix
libsdl1.2debian_1.2.15-9ubuntu1_amd64.deb rolled it back
libsdl1.2debian_1.2.15-9ubuntu2_amd64.deb fixed it for good, had this changelog entry:
libsdl1.2 (1.2.15-9ubuntu2) utopic; urgency=medium
* Restore accidentally-clobbered changes from 1.2.15-8ubuntu2.
[ Timo Jyrinki ]
* debian/patches/sdl-check-for-SDL_VIDEO_X11_BACKINGSTORE.patch:
- Restore old backingstore behavior to prevent tearing
(LP: #1280665)
Had to revert HUNDREDS of packages one at a time to find this! Any kind of anti-tearing behavior can be resource intensive, I've never had tearing problems in games with r600 but do need to use vsync with video players.
Today I posted this in https://bugs.launchpad.net/ubuntu/+s.../+bug/1293314:
This bug was finally resolved with updates to sdl, used by all the games I saw it in. When I first changed repos to move to Utopic Unicorn, a new SDL package returned both Critter and Scorched3d to full performance. Then another update reverted some change, and performance fell right back to where it had been. Finally a 3ed update fixed it again, hopefully for good.
libsdl1.2debian_1.2.15-8ubuntu2_amd64.deb brought the original fix
libsdl1.2debian_1.2.15-9ubuntu1_amd64.deb rolled it back
libsdl1.2debian_1.2.15-9ubuntu2_amd64.deb fixed it for good, had this changelog entry:
libsdl1.2 (1.2.15-9ubuntu2) utopic; urgency=medium
* Restore accidentally-clobbered changes from 1.2.15-8ubuntu2.
[ Timo Jyrinki ]
* debian/patches/sdl-check-for-SDL_VIDEO_X11_BACKINGSTORE.patch:
- Restore old backingstore behavior to prevent tearing
(LP: #1280665)
Had to revert HUNDREDS of packages one at a time to find this! Any kind of anti-tearing behavior can be resource intensive, I've never had tearing problems in games with r600 but do need to use vsync with video players.