NVIDIA/Optimus
NVIDIA Optimus is Article description::a proprietary technology that seamlessly switches between two GPUs. It is typically used on systems that have an integrated Intel GPU and a discrete NVIDIA GPU. The main benefit of using NVIDIA Optimus is to extend battery life by providing maximum GPU performance only when needed.
For an open source implementation of NVIDIA Optimus, see Bumblebee.
Installation
Kernel
Since NVIDIA Optimus will be using the integrated Intel graphics for modesetting, the following kernel options will need to be enabled:
Device Drivers --->
Graphics Support --->
Direct Rendering Manager (Xfree86 4.1.0 and higher DRI support) --->
[*] Enable legacy fbdev support for your modesetting driver
<*> Intel 8xx/9xx/G3x/G4x/HD Graphics
[*] Enable preliminary support for prerelease Intel hardware by default
This option has been removed in Kernels above 4.10.
In the case that something should go wrong, it is recommended to have live media to assist in reverting any changes. Having a Gentoo Minimal Install CD, SystemRescueCD (which is a Gentoo based recovery image), or a LiveUSB around work nicely for this purpose. If you choose to proceed without having a "just in case" alternative boot method proceed with extreme caution!
At the time this article was written version 343.36 of x11-drivers/nvidia-drivers was the most recent (stable) version of the driver in the Portage tree, therefore examples that reference a specific version will presume version 343.36 is being used. When a newer version of the driver is released, or if an older version is selected, simply substitute 343.36 for the desired version.
USE flags
USE flags for x11-drivers/nvidia-drivers NVIDIA Accelerated Graphics Driver
X
|
Install the X.org driver, OpenGL libraries, XvMC libraries, and VDPAU libraries |
compat
|
Install non-GLVND libGL for backwards compatibility |
dist-kernel
|
Enable subslot rebuilds on Distribution Kernel upgrades |
driver
|
Install the kernel driver module |
kms
|
Enable support for kernel mode setting (KMS) |
multilib
|
On 64bit systems, if you want to be able to compile 32bit and 64bit binaries |
static-libs
|
Build static versions of dynamic libraries as well |
tools
|
Install additional tools such as nvidia-settings |
uvm
|
Install the Unified Memory kernel module (nvidia-uvm) for sharing memory between CPU and GPU in CUDA programs |
wayland
|
Enable dev-libs/wayland backend |
Emerge
Installing NVIDIA drivers is easy, run the following:
root #emerge --ask x11-drivers/nvidia-driversSince xorg 1.18 if the intel screen is always disabled enable
glamor USE flag on xorg-serverConfiguration
Configuring a system to use NVIDIA's proprietary driver is not easy as the installation. There are several configuration files that will need to be modified in order for a system to work properly.
Kernel modules
If the user has chosen to not use built-in modules, then the init system should load the necessary modules on system boot. If /proc/config.gz (or /boot/config-*-gentoo) is available, this can verified by running the following command:
user $zgrep "CONFIG_MODULES=" /proc/config.gzIf the output returns CONFIG_MODULES set to N, then the kernel will need recompiled with support to load modules. Information about that can be found over here. After module loading support has been added, return to this article and continue reading.
Create a new file called nvidia.conf in the /etc/modules-load.d directory. It should contain the NVIDIA module name:
/etc/modules-load.d/nvidia.confnvidia
OpenRC
Verify the modules init script has been added to the boot runlevel (it should be by default, but double check):
root #rc-update add modules bootThe output should look like:
* rc-update: modules already installed in runlevel `boot'; skipping
Systemd
Check the status of the systemd-modules-load.service to verify things are running smoothly. If issues arise this service unit will be the place to check:
root #systemctl start systemd-modules-load.servicexorg.conf
The best way to set the system's xorg.conf correctly would be to read the documentation NVIDIA has provided. The documentation can be found in a couple of locations. To save time, consider reading only the pages on Optimus and XRandR, as they are vital to correct configuration. If the driver has already been emerged (done in the installation step above), the documentation can be found locally at /usr/share/doc/nvidia-drivers-*/README.bz2.
Example: Use the less command to read the local documentation:
user $less /usr/share/doc/nvidia-drivers-*/README.bz2It is also possible to read the documentation at NVIDIA's website by following these (external) links:
http://us.download.nvidia.com/XFree86/Linux-x86_64/343.36/README/optimus.html
http://us.download.nvidia.com/XFree86/Linux-x86_64/343.36/README/randr14.html
Replace 343.36 with your version of nvidia-drivers e.g. 390.42 to get the most suitable configuration.
For a quick example here on the wiki, view this xorg.conf file.
The xorg.conf is an example here and since the configuration might change in any version of nvidia-drivers you had better consult the NVIDIA document noted above.
How to find BusID
Invoke lspci the BusID is at the beginning of each device:
01:00.0 3D controller: NVIDIA Corporation GK104M [GeForce GTX 870M] (rev a1)
Where 01:00.0 is BusID.
Using a specific monitor via EDID
It is probably best to first try a simple configuration first like described in the NVIDIA driver manual:
http://us.download.nvidia.com/XFree86/Linux-x86_64/346.22/README/randr14.html
Saving the monitor's EDID
Ensure the currently running kernel has CONFIG_I2C_CHARDEV enabled and the resulting i2c-dev module loaded or compiled monolithically for read-edid to work.
Some laptops/notebooks may benefit from saving the EDID screen information to a file so it can be passed to the Intel modesetting driver. The EDID information can be saved using the read-edid utility.
root #emerge --ask x11-misc/read-edidroot #mkdir -p /lib/firmware/edidroot #get-edid > /lib/firmware/edid/1920x1080_Clevo_W670SR.binThe EDID information is provided to the Intel GPU (Graphics Processing Unit) by specifying its location in the kernel boot parameter:
drm_kms_helper.edid_firmware=edid/1920x1080_clevo_W670SR.bin
If the GRUB2 bootloader is being used, this can be configured in the file /etc/default/grub
/etc/default/grub<syntaxhighlight lang="bash">GRUB_CMDLINE_LINUX_DEFAULT="drm_kms_helper.edid_firmware=edid/1920x1080_clevo_W670SR.bin" GRUB_GFXMODE=1920x1080</syntaxhighlight>
Note: If using Sabayon Linux, the kernel boot parameters should be specified in the /etc/default/sabayon-grub file instead of /etc/default/grub file.
Example xorg.conf for EDID
See EDID xorg.conf Example to view an example xorg.conf using an EDID for a specific monitor.
Before starting X
Per NVIDIA's instructions, the following commands are required before starting X:
<syntaxhighlight lang="bash">xrandr --setprovideroutputsource modesetting NVIDIA-0 xrandr --auto</syntaxhighlight>
This is to say any Display Manager that starts X-Windows then asks the user to log in will result in a black screen unless the above xrandr commands are run before asking the user to log in.
The xrandr commands must be added to the system's X session start up scripts (such as ~/.xinitrc) in order for the X display to start using modesetting. Failure to do so will result in a black screen.
NOTE: If you get a black screen with no back-lighting from the previous steps, creating .xsessionrc and placing the xinitrc commands in there COULD fix it.
Use the xrandr command to find the appropriate graphics device:
root #xrandr --listprovidersDisplay manager configuration
The following shows a list of where to add the required xrandr commands, sorted by desktop.
If you are sure you have done every step accordingly and still you get a black screen, chances are that the display manager your are using might have problems. Switch to another display manager like x11-misc/lightdm.
Qingy
For menu option (A) KDE-4
Add the xrandr commands to the end of the /etc/X11/Sessions/KDE-4 file:
/etc/X11/Sessions/KDE-4KDE-4's X session file<syntaxhighlight lang="bash">xrandr --setprovideroutputsource modesetting NVIDIA-0 xrandr --auto</syntaxhighlight>
For menu option (B) your .xsession
Add the xrandr commands to the end of the ~/.xsession file.
Qingy DirectFB
In the /etc/directfbrc configuration file. It is necessary to set the busid variable to the BusID of the Intel graphics card as reported by the lspci command:
root #lspci | grep VGAFor example, if lspci says the Intel graphics card is on BusID 00:02.0, then add the following line to /etc/directfbrc
/etc/directfbrc<syntaxhighlight lang="bash">busid=0:02:0</syntaxhighlight>
The Console Display Manager (CDM)
Add the xrandr commands to ~/.xinitrc file:
Simple Desktop Display Manager (SDDM)
First, edit the sddm configuration to have it look for the commands:
/etc/sddm.conf<syntaxhighlight lang="ini">[X11] DisplayCommand=/etc/sddm/scripts/Xsetup</syntaxhighlight>
Next create the directory /etc/sddm/scripts
root #mkdir -p /etc/sddm/scripts.
Then, Add the xrandr commands to the /etc/sddm/scripts/Xsetup file
/etc/sddm/scripts/Xsetup<syntaxhighlight lang="bash">#!/bin/sh xrandr --setprovideroutputsource modesetting NVIDIA-0 xrandr --auto</syntaxhighlight>
Finally set execute permissions on the file /etc/sddm/scripts/Xsetup.
root #chmod a+x /etc/sddm/scripts/XsetupMint Desktop Manager (MDM)
Add the xrandr commands to the /etc/X11/mdm/Init/Default file:
X Display Manager (XDM)
Add the xrandr commands to the /usr/lib/X11/xdm/Xsetup_0 file and protect them like described above.
NOTE: if the system is a 32-bit system, add the commands to the /usr/lib64/X11/xdm/Xsetup_0 file.
If using a 64-bit system, edit the /etc/X11/xdm/xdm-config configuration file and change the following line to point to the Xsetup_0 file created above:
/etc/X11/xdm/xdm-configX Display Manager ExampleDisplayManager._0.setup: /usr/lib/X11/xdm/Xsetup_0
LXDE Display Manager (LXDM)
Add the following lines to /etc/lxdm/LoginReady:
/etc/lxdm/LoginReadyLXDE Display Manager Example<syntaxhighlight lang="bash">xrandr --setprovideroutputsource modesetting NVIDIA-0 xrandr --auto</syntaxhighlight>
Gnome Display Manager (GDM)
Create two .desktop files:
/etc/xdg/autostart/optimus.desktop & /usr/share/gdm/greeter/autostart/optimus.desktopDesktop Entries<syntaxhighlight lang="ini">[Desktop Entry] Type=Application Name=Optimus Exec=sh -c "xrandr --setprovideroutputsource modesetting NVIDIA-0; xrandr --auto" NoDisplay=true X-GNOME-Autostart-Phase=DisplayServer</syntaxhighlight>
Make sure that GDM uses X as default backend (this does only affect gnome-base/gdm. gnome-base/gnome-shell will still use wayland when USE="wayland" is enabled):
/etc/gdm/custom.confcustom.conf<syntaxhighlight lang="ini"># GDM configuration storage [daemon] # Uncoment the line below to force the login screen to use Xorg WaylandEnable=false [security] [xdmcp] [chooser] [debug] # Uncomment the line below to turn on debugging #Enable=true</syntaxhighlight>
LightDM
Prepare a script in /usr/local/bin/:
/usr/local/bin/prepare-optimus.sh<syntaxhighlight lang="bash">#!/bin/bash xrandr --setprovideroutputsource modesetting NVIDIA-0 xrandr --auto # Run the rest of the arguments. # - $($@)</syntaxhighlight>
Make it executable and update lightdm.conf with the location of that script:
/etc/lightdm/lightdm.conf[Seat:*] # display-setup-script = Script to run when starting a greeter session (runs as root) display-setup-script=/usr/local/bin/prepare-optimus.sh
Troubleshooting
Since there are many files to configure and because the NVIDIA's proprietary support for Optimus in Linux is buggy, it is rather easy to create a faulty Optimus configuration. It is possible something was typed incorrectly, or a certain configuration was not compatible with the hardware being used. Whatever the case, a broken configuration means that debugging is required.
To debug, carefully read the logs from dmesg (/var/log/dmesg) and Xorg (/var/log/Xorg.0.log) with a favorite text editor; they are the best indicators to find issues. If something irregular is discovered, make changes to the respective configuration files. Other areas to inspect for debugging include any of the configuration files that were modified through the course of this article (the kernel's {Path|.config}}, kernel boot parameters passed at /etc/default/grub, the Xorg's /etc/X11/xorg.conf file, etc.). Continue checking the files as necessary then reboot the system and try again. Many attempts may be required in order to obtain a working configuration! It is not exciting process; time could be spent on something more interesting, but if debugging is required in order to get Optimus working then it needs to happen.
In a shell to quickly find warnings and errors:
grep -E 'WW|EE' /var/log/Xorg.0.logWhen viewing /var/log/Xorg.0.log using a text editor such as app-editors/vim, search for
(WW) or (EE) to quickly find warnings and errors. This will speed up debugging time considerably.To aid in distinguishing between important and unimportant messages in /var/log/dmesg and /var/log/Xorg.0.log files, working examples have been provided at these sub-articles:
Specific models
- Lenovo Thinkpad W530 - In short, for all the screens to work, set the configuration to discrete mode in the motherboard firmware.
D-Bus
Xorg
See also
- Nouveau & nvidia-drivers switching — describes how to switch between NVIDIA's binary driver and the open source nouveau driver.
- NVIDIA/nvidia-drivers — The x11-drivers/nvidia-drivers package contains the proprietary graphics driver for NVIDIA graphic cards.