Here is a bug report I managed to capture using the 295.49 driver - may or may not prove useful.
** Attachment added: "Nvidia Bug Report" https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers/+bug/982710/+attachment/3164294/+files/nvidia-bug-report.log.gz -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/982710 Title: [regression] Nvidia 295.40 driver is extremely slow To manage notifications about this bug go to: https://bugs.launchpad.net/nvidia-drivers-ubuntu/+bug/982710/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs