https://bugs.freedesktop.org/show_bug.cgi?id=98146
--- Comment #21 from Mike Lothian mike@fireburn.co.uk --- To stop tearing you'll need to be running kernel 4.10 or newer, as that contains the i915 fences work
You don't need to launch the steam app with DRI_PRIME, you just chance the individual games to launch with it. It'll save you power when you're not gaming