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. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1293314 Title: Severe performance regression with xserver 1.15 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1293314/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp