I have a Packard-Bell EasyNote laptop and have recently upgraded from Ubuntu 17.10 to 18.04. The laptop uses the nVidia Optimus system, meaning it has an Intel GPU for most tasks to conserve battery power but for graphic intensive tasks it has a nVidia GeForce GT 540M.
To switch between the GPUs I use the Bumblebee package. Choosing which nVidia driver to use has always been a problem in the past and since I upgraded to 17.04 a year ago I have simply used the builtin Nouveau driver. After reading that the proprietary drivers work under 18.04 I have tried updating to proprietary drivers but nothing seems to work.
~$ ubuntu-drivers devices
returns:
== /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0 ==
modalias : pci:v000010DEd00000DF4sv00001025sd00000512bc03sc00i00
vendor : NVIDIA Corporation
model : GF108M [GeForce GT 540M]
driver : nvidia-340 - distro non-free
driver : nvidia-304 - third-party free
driver : nvidia-driver-390 - third-party free recommended
driver : xserver-xorg-video-nouveau - distro free builtin
But after installing nvidia-driver-390 (using both apt-get from the command line and Synaptic) the command nvidia-smi returns:
NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running.
I would be extremely grateful if somebody would give a step by step instruction for installing a working nVidia driver.
