Comment # 3 on bug 1201995 from Stefan Dirsch

With that nvidia driver should work without need for any more options. But I
would recommend to use 

  prime-select nvdiia

instead to make use of your nvidia card, although it has a higher power
consumption. Also you probably can't use your external outputs without.

I'm afraid without proprietary nvidia driver you can only use Intel GPU and you
need to disable the nvidia GPU explicitely by blacklisting the nouveau driver
somehow.

Also you can make things easier by disabling one of the GPU. But probably you
can only disable Intel GPU. Check your BIOS/firmware.