NVIDIA/Optimus

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See also
PRIME GPU Rendering is a preferred solution by many users and should be looked at for support before trying Optmis. More information can be found at Hybrid_graphics

NVIDIA Optimus is 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:

KERNEL Linux kernel 4.3.3+
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
Warning
This option has been removed in Kernels above 4.10.
Important
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 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!
Note
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 When a newer version of the driver is released, or if an older version is selected, simply substitute 343.36 for the desired version.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 Add support for X11
+modules Build the kernel modules
+static-libs Install the XNVCtrl static library for accessing sensors and other features
+strip Allow symbol stripping to be performed by the ebuild for special files
+tools Install additional tools such as nvidia-settings
dist-kernel Enable subslot rebuilds on Distribution Kernel upgrades
kernel-open Use the open source variant of the drivers (Turing/Ampere+ GPUs only, aka GTX 1650+ -- recommended with >=560.xx drivers if usable)
modules-compress Install compressed kernel modules (if kernel config enables module compression)
modules-sign Cryptographically sign installed kernel modules (requires CONFIG_MODULE_SIG=y in the kernel)
persistenced Install the persistence daemon for keeping devices state when unused (e.g. for headless)
powerd Install the NVIDIA dynamic boost support daemon (only useful with specific laptops, ignore if unsure)
wayland Enable dev-libs/wayland backend
Data provided by the Gentoo Package Database · Last update: 2024-11-04 13:27 More information about USE flags

Emerge

Installing NVIDIA drivers is easy, run the following:

root #emerge --ask x11-drivers/nvidia-drivers
Note
Since xorg 1.18 if the intel screen is always disabled enable glamor USE flag on xorg-server

Also, Make sure Xrandr is installed, as it is needed later in the setup (it is always pulled in automatically). If not, emerge it as well:

root #emerge --ask x11-apps/xrandr

Configuration

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.gz
CONFIG_MODULES=y

If 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:

FILE /etc/modules-load.d/nvidia.conf
nvidia

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 boot

The 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.service

xorg.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.bz2

It 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.

Warning
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 the busid

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.

Automatic Xorg.conf Configuration

The driver comes with an automatic tool to create an appropriate Xorg.conf for using Optimus. If you have a custom xorg.conf, it is prudent to create a backup just in case (although the tool makes a backup of its own).

root #nvidia-xconfig --prime

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

Important
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-edid
root #mkdir -p /lib/firmware/edid
root #get-edid > /lib/firmware/edid/1920x1080_Clevo_W670SR.bin

The 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

FILE /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="drm_kms_helper.edid_firmware=edid/1920x1080_clevo_W670SR.bin"
GRUB_GFXMODE=1920x1080

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:

CODE XRandR commands:
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto

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.

Warning
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 --listproviders

Display manager configuration

The following shows a list of where to add the required xrandr commands, sorted by desktop.

Warning
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:

FILE /etc/X11/Sessions/KDE-4KDE-4's X session file
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto
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 VGA
00:02.0 VGA compatible controller: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller (rev 06)

For example, if lspci says the Intel graphics card is on BusID 00:02.0, then add the following line to /etc/directfbrc

FILE /etc/directfbrc
busid=0:02:0

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:

FILE /etc/sddm.conf
[X11]
DisplayCommand=/etc/sddm/scripts/Xsetup

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

FILE /etc/sddm/scripts/Xsetup
#!/bin/sh
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto

Finally set execute permissions on the file /etc/sddm/scripts/Xsetup.

root #chmod a+x /etc/sddm/scripts/Xsetup

Mint Desktop Manager (MDM)

Add the xrandr commands to the /etc/X11/mdm/Init/Default file:

X Display Manager (XDM)

 As of 2020-07-28, the information in this section is probably outdated. You can help the Gentoo community by verifying and updating this section.

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:

FILE /etc/X11/xdm/xdm-configX Display Manager Example
DisplayManager._0.setup: /usr/lib/X11/xdm/Xsetup_0

LXDE Display Manager (LXDM)

Add the following lines to /etc/lxdm/LoginReady:

FILE /etc/lxdm/LoginReadyLXDE Display Manager Example
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto

Gnome Display Manager (GDM)

Create two .desktop files:

FILE /etc/xdg/autostart/optimus.desktop & /usr/share/gdm/greeter/autostart/optimus.desktopDesktop Entries
[Desktop Entry]
Type=Application
Name=Optimus
Exec=sh -c "xrandr --setprovideroutputsource modesetting NVIDIA-0; xrandr --auto"
NoDisplay=true
X-GNOME-Autostart-Phase=DisplayServer

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):

FILE /etc/gdm/custom.confcustom.conf
# 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

LightDM

Prepare a script in /usr/local/bin/:

FILE /usr/local/bin/prepare-optimus.sh
#!/bin/bash
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto
# Run the rest of the arguments.
# -
$($@)

Make it executable and update lightdm.conf with the location of that script:

FILE /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.

Note
In a shell to quickly find warnings and errors: grep -E 'WW|EE' /var/log/Xorg.0.log
Note
When 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


In case Xorg fails immediately after boot but works fine when launched later, it might be due to a race condition in which the Intel driver doesn't load in time and Xorg complains that there is no /dev/dri/card0. In that case you should load the Intel driver to the initramfs:

FILE /etc/dracut.conf.d/nvidiaoptimus.conf
force_drivers+=" i915 "

Regenerate the initramfs image:

root #dracut --force

See also

External resources

Retrieved from "https://wiki.gentoo.org/index.php?title=NVIDIA/Optimus&oldid=1305936"