You must to do is add "nouveau.pstate=1" in grub linux line only. Once.
And when you want to play some game, reclock with only one command, something like:
$ echo 0f > /sys/class/drm/card0/device/pstate (07, 0a, 0e, 0f) are states of GPU and play!!! See the difference with gtx650: $ glmark2 -s 1920x1080 --annotate not reclocked: glmark2 Score: 219 reclocked: glmark2 Score: 1269
