Comment 34 for bug 1386721

useful info for owners intel cards with i915 driver - i managed to resolve the issue with video lags by driver (installing xserver-xorg-video-intel) from https://launchpad.net/~xorg-edgers/+archive/ubuntu/ppa/+packages?field.name_filter=intel&field.status_filter=published&field.series_filter=
now all works smoothly and fast, similarly to 14.04