Switching between Intel and NVIDIA graphics processors on a laptop with NVIDIA Optimus hardware running Gentoo Linux

I have a Clevo W230SS laptop with an Intel HD 4600 IGP and an NVIDIA GeForce GTX 860M GPU, running KDE in Gentoo Linux. I could have installed Bumblebee in order to use the NVIDIA GPU with selected applications, but I decided instead to switch manually between the graphics processors. To achieve this I created two Desktop Configuration Files with nice icons on my Desktop, to launch two simple Bash scripts which configure my installation for the desired graphics processor, which will then be used when I next login to KDE. All the necessary files are listed below for Gentoo Linux. You would need to modify them if you are using a different distribution.

The Bash script ~/intel.sh contains the following:

#!/bin/bash
echo
echo "Your installation is currently configured to use the following graphics processor:"
echo
GPU=`eselect opengl list | grep \* | awk '{ print $2 }'`
if [ "$GPU" = "xorg-x11" ]; then
  echo "Intel HD 4600 Integrated Graphics Processor"
  echo
  echo "You do not need to do anything. Please close this window."
elif [ "$GPU" = "nvidia" ]; then
  echo "NVIDIA GeForce GTX 860M"
  echo
  echo "This script will configure your installation to use the"
  echo "Intel HD 4600 Integrated Graphics Controller all the time."
  echo
  echo "Enter your own password."
  echo
  sudo eselect opengl set xorg-x11
  sudo cp /home/fitzcarraldo/Xsetup.intel /usr/share/config/kdm/Xsetup
  sudo cp /home/fitzcarraldo/xorg.conf.intel /etc/X11/xorg.conf
  echo
  echo "Now you should logout to restart X Windows."
fi

The Bash script ~/nvidia.sh contains the following:

#!/bin/bash
echo
echo "Your installation is currently configured to use the following graphics processor:"
echo
GPU=`eselect opengl list | grep \* | awk '{ print $2 }'`
if [ "$GPU" = "nvidia" ]; then
  echo "NVIDIA GeForce GTX 860M"
  echo
  echo "You do not need to do anything. Please close this window."
elif [ "$GPU" = "xorg-x11" ]; then
  echo "Intel HD 4600 Integrated Graphics Processor"
  echo
  echo "This script will configure your installation to use the NVIDIA GeForce GTX 860M GPU all the time."
  echo
  echo "Enter your own password."
  echo
  sudo eselect opengl set nvidia
  sudo cp /home/fitzcarraldo/Xsetup.nvidia /usr/share/config/kdm/Xsetup
  sudo cp /home/fitzcarraldo/xorg.conf.nvidia /etc/X11/xorg.conf
  echo
  echo "Now you should logout to restart X Windows."
fi

I created two files, xorg.conf.intel and xorg.conf.nvidia, in my home directory. The corresponding Bash script copies the applicable file to the directory /etc/X11/ to create an xorg.conf file with the correct contents for the graphics processor.

The file ~/xorg.conf.intel contains the following:

Section "Device" 
   Identifier  "Intel Graphics" 
   Driver      "intel" 
   Option      "AccelMethod" "sna" 
   Option      "TearFree" "true" 
EndSection

The file ~/xorg.conf.nvidia contains the following:

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "nvidia" 0 0
    Inactive       "intel"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "nvidia"
    Driver         "nvidia"
    BusID          "PCI:1:0:0"
EndSection

Section "Device"
    Identifier     "intel"
    Driver         "modesetting"
    BusID          "PCI:0:2:0"
EndSection

Section "Screen"
    Identifier     "nvidia"
    Device         "nvidia"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "UseDisplayDevice" "none"
    SubSection     "Display"
        Depth       24
#        Modes      "nvidia-auto-select"
        Virtual     1920 1080
    EndSubSection
EndSection

Section "Screen"
    Identifier     "intel"
    Device         "intel"
    Monitor        "Monitor0"
EndSection

I created two files, Xsetup.intel and Xsetup.nvidia, in my home directory. The corresponding Bash script copies the applicable file to the directory /usr/share/config/kdm/ to create an Xsetup file with the correct contents for the graphics processor.

The file ~/Xsetup.intel is listed below. As you can see, everything is commented out in the file.

#! /bin/sh
# Xsetup - run as root before the login dialog appears

#xconsole -geometry 480x130-0-0 -notify -verbose -fn fixed -exitOnFail -file /dev/xconsole &

The file Xsetup.nvidia is listed below. As you can see, it contains two xrandr commands.

#! /bin/sh
# Xsetup - run as root before the login dialog appears

#xconsole -geometry 480x130-0-0 -notify -verbose -fn fixed -exitOnFail -file /dev/xconsole &
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto

I downloaded nice icons from the Web for the Desktop Configuration Files and put them in the directory ~/Pictures/Icons/.

The file ~/Desktop/Select\ Intel\ HD\ Graphics.desktop is listed below.

[Desktop Entry]
Comment[en_GB]=Run a script to configure your installation to use Intel Integrated Graphics when you restart X Windows
Comment=Run a script to configure your installation to use Intel Integrated Graphics when you restart X Windows
Exec=/home/fitzcarraldo/intel.sh
GenericName[en_GB]=Configure your installation to use Intel HD Graphics
GenericName=Configure your installation to use Intel HD Graphics
Icon=/home/fitzcarraldo/Pictures/Icons/intel_hd_graphics_icon.png
MimeType=
Name[en_GB]=Intel HD Graphics
Name=Intel HD Graphics
Path=
StartupNotify=true
Terminal=true
TerminalOptions=\s--noclose
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=fitzcarraldo

The file ~/Desktop/Select\ NVIDIA\ GPU.desktop is listed below.

[Desktop Entry]
Comment[en_GB]=Run a script to configure your installation to use the NVIDIA GeForce GTX 860M GPU when you restart X Windows
Comment=Run a script to configure your installation to use the NVIDIA GeForce GTX 860M GPU when you restart X Windows
Exec=/home/fitzcarraldo/nvidia.sh
GenericName[en_GB]=Configure your installation to use the NVIDIA GeForce GTX 860M GPU
GenericName=Configure your installation to use the NVIDIA GeForce GTX 860M GPU
Icon=/home/fitzcarraldo/Pictures/Icons/nvidia_icon.png
MimeType=
Name[en_GB]=NVIDIA GPU
Name=NVIDIA GPU
Path=
StartupNotify=true
Terminal=true
TerminalOptions=\s--noclose
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=fitzcarraldo

Don’t forget to make all the Bash script files and .desktop files executable. All I have to do is double-click on either icon on the Desktop and a Konsole window pops up and tells me what to do. Next time I log in, the graphics processor I selected will be active.

My thanks go to Gentoo Linux user arthanis for showing me the way in the Gentoo Forums thread [SOLVED] Optimus and Nvidia.

Update (September 24, 2016): I upgraded xorg-server from 1.17.4 to 1.18.4 today and had to change the following line in /etc/X11/xorg.conf:

Screen 0 "nvidia" 0 0

to:

Screen 1 "nvidia" 0 0

See the Gentoo Forums post What’s up with xorg-server 1.18 and Optimus? for further details

Update (September 6, 2017): KDM is not used for KDE Plasma 5, so the line in the Bash scripts ~/intel.sh and ~/nvidia.sh to copy a file to /usr/share/config/kdm/Xsetup can be deleted. However, the replacement Display Manager needs to be configured to cater for the NVIDIA GPU and Intel HD Graphics. I use LightDM on my Clevo W230SS laptop that has Optimus hardware, and the method of configuring LightDM to cater for the two different graphics processors is given in my blog post Getting KDE Plasma 5 to work with the NVIDIA closed-source driver in Gentoo Linux.