For using external display, I started to find out how to enable discretion display card on Ubuntu with my new W530.
Previously I have installed bumblebee and nvidia-current page on my laptop and have nvidia driver work with optirun, unfortunately bumblebee seems not work well with external display, I cannot turn to use discretion card mode when external display connected.
1. Turn the display mode to discretion mode only (without optimus detection), booting failed to continue after ram image loaded. Seems something wrong with bumblebee or the driver package installed.
2. Turn display mode back to optimus mode and start system, then remove bumblebee and driver packages installed.
3. With default kernel and nouveau driver, the external display is supported when system configured to use discretion mode, but seems it is not so stable and the X keep crashing.
4. Install the nvidia proprietary driver package. need to disable nouveau driver and reboot in the installation.
5. Reboot the system, turn to discretion mode.
