So far I think we've established that it is not a rouge CPU hog that is blocking the system. Having to restart the system rather the session, also lends credence to that it is not a simple userspace or even gfx driver issue.
On the theory that the GPU goes nuts, download and build http://cgit.freedesktop.org/xorg/app/intel-gpu-tools/ (maybe apt-get install intel-gpu-tools if you feel lucky), then run intel_gpu_top. Except for running gtkperf etc, the GPU should be lightly loaded. On the theory that the CPU goes nuts, apt-get install powertop latencytop, and run the pair of those looking for abnormalities. For powertop, the CPU should be waking up and hitting max frequency when busy and hitting C6+ when idle. latencytop should help identify what is taking time (not necessarily cpu cycles) to complete. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/1189645 Title: General lag under desktop environments To manage notifications about this bug go to: https://bugs.launchpad.net/xserver-xorg-video-intel/+bug/1189645/+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