The problem appears to be caused by the window manager or compositor. On request from NVIDIA, I disabled the window manager on the affected machine and ran a raw X server:
sudo service lightdm stop sudo Xorg & xlogo & and then ran glxgears full-screen: glxgears -geometry 2400x1900+10+10 This worked well. glxgears is only being used as a simple test application. The Chrome web browser's GPU accelerated rendering path is broken in the same situations that glxgears fails to work well. I've upgraded NVIDIA's drivers to 295.53 but they have the same behavior as the 295.40 drivers when running within Unity. It looks to me like the compositor in Precise doesn't respect the GLX swap interval requested by OpenGL applications, and this is causing the Chrome browser to run open-loop, spamming the GPU with commands. On request from NVIDIA, here is the output of nvidia-bug-report.sh on the machine while glxgears was running badly, with the 295.53 drivers. ** Attachment added: "NVIDIA bug report" https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers/+bug/988079/+attachment/3149844/+files/nvidia-bug-report.log.gz -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to nvidia-graphics-drivers in Ubuntu. https://bugs.launchpad.net/bugs/988079 Title: Dismal performance on HP Z600 with 30" landscape monitor To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers/+bug/988079/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : [email protected] Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
