I'm running nvidia drivers 367.57 on a precision 5510 (Quadro M1000M + skylake). It's connected to an external monitor via Displayport through a Dell D3100 dock. I'm running Ubuntu 16.10 with kernel 4.8.1.
I've got bumblebee installed, and it's working correctly when using Intel graphics. When I switch to the nvidia graphics (and of course, bumblebee can't work), the external monitor shows output, but the laptop screen is completely blank. xrandr also sees only the second screen - it doesn't even list the laptop one.
The other issue I'm seeing is that when using the Intel graphics, bumblebee works, but the performance is significantly worse. e.g. glxspheres running on the second monitor without optirun is 1/s, with optirun is 200/s, but when switched to the nvidia graphics, it's 2000/s. Furthermore, with bumblebee, dragging on the second monitor is slow, as is typing in the terminal. These issues are non-existent when using nvidia graphics only.
Are these issues common? Are there known workarounds?
Update: Also, with bumblebee, when running glxspheres on the internal screen, intel gives around 55-60/s, while optirun glxspheres gives the same as on the external screen - around the 200 mark.
Update 2 I've hooked the laptop to a Dell 2715K monitor with a Plugable Thunderbolt 3 to dual displayport adaptor, and it shows output to both the laptop screen, and the external monitor with both intel, and nvidia (only) graphics. So, the laptop screen is blank when using Prime when the laptop's connected with the D3100 over USB, but is fine when connected via thunderbolt 3. Any idea how to resolve this?