Lenovo P50

Ubuntu 16.04.3 working on Lenovo P50 with NVIDIA drivers

So far it is (at least for me) very painful to use the P50 with multiple screens. The following steps should bring it to a usable state.

1. Disable hybrid graphic cards in the bios under the display settings.
2. Install the nvidia drivers through the software center (version 375)
3. Do not edit anything in the Nvidia X Server settings.
4. Make sure the have a proper ~/.config/monitors.xml
5. Copy this properly working monitors xml into the lighdm: sudo cp .config/monitors.xml /var/lib/lightdm/.config
6. Maybe protect the monitors file such that it can not be changed: sudo chattr +i ~/.config/monitors.xml

An example monitors.xml

<monitors version="1">
  <configuration>
      <clone>no</clone>
      <output name="DP-3.1">
          <vendor>DEL</vendor>
          <product>0xa0b8</product>
          <serial>0x3048374c</serial>
          <width>1920</width>
          <height>1200</height>
          <rate>60</rate>
          <x>1080</x>
          <y>720</y>
          <rotation>normal</rotation>
          <reflect_x>no</reflect_x>
          <reflect_y>no</reflect_y>
          <primary>yes</primary>
      </output>
      <output name="DP-0">
      </output>
      <output name="DP-1">
      </output>
      <output name="DP-2">
      </output>
      <output name="DP-3">
      </output>
      <output name="DP-4">
          <vendor>SHP</vendor>
          <product>0x143b</product>
          <serial>0x00000000</serial>
      </output>
      <output name="DP-5">
      </output>
      <output name="DP-6">
      </output>
      <output name="DP-3.2">
          <vendor>LEN</vendor>
          <product>0x60c8</product>
          <serial>0x01010101</serial>
          <width>1920</width>
          <height>1080</height>
          <rate>60</rate>
          <x>0</x>
          <y>0</y>
          <rotation>left</rotation>
          <reflect_x>no</reflect_x>
          <reflect_y>no</reflect_y>
          <primary>no</primary>
      </output>
  </configuration>
</monitors>