Difference between revisions of "NVIDIA Optimus"

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* [[#Use Intel graphics only]] - saves power, because NVIDIA GPU will be completely powered off.
 
* [[#Use Intel graphics only]] - saves power, because NVIDIA GPU will be completely powered off.
 
* [[#Use NVIDIA graphics only]] - gives more performance than Intel graphics, but drains more battery (which is not welcome for mobile devices).
 
* [[#Use NVIDIA graphics only]] - gives more performance than Intel graphics, but drains more battery (which is not welcome for mobile devices).
* Using both (use NVIDIA GPU when needed and keep it powered off to save power):
+
* Using both (use NVIDIA GPU when need and power it off to save power when not needed):
** [[#Using optimus-manager]] - switches graphics with a single command (logout and login required to take effect). It achieves maximum performance out of NVIDIA GPU and switches it off if not in use.
+
** [[#Using optimus-manager]] - an unofficial implementation of Nvidia's {{ic|nvidia-prime}} for Arch Linux. Due to its simplicity to use without compromising performance, it should be default choice for majority of users.
** [[#Using nvidia-xrun]] - run separate X session on different TTY with NVIDIA graphics. It achieves maximum performance out of NVIDIA GPU and switches it off if not in use.
+
** [[#Using nvidia-xrun]] - run separate X session on different TTY with NVIDIA graphics.
 
** [[#Using Bumblebee]] - provides Windows-like functionality by allowing to run selected applications with NVIDIA graphics while using Intel graphics for everything else. Has significant performance issues and does not support [[Vulkan]].
 
** [[#Using Bumblebee]] - provides Windows-like functionality by allowing to run selected applications with NVIDIA graphics while using Intel graphics for everything else. Has significant performance issues and does not support [[Vulkan]].
 
** [[#Using nouveau]] - offers poorer performance (compared to the proprietary NVIDIA driver) and may cause issues with sleep and hibernate. Does not work with latest NVIDIA GPUs.
 
** [[#Using nouveau]] - offers poorer performance (compared to the proprietary NVIDIA driver) and may cause issues with sleep and hibernate. Does not work with latest NVIDIA GPUs.

Revision as of 07:49, 26 August 2019

NVIDIA Optimus is a technology that allows an Intel integrated GPU and discrete NVIDIA GPU to be built into and accessed by a laptop.

Available methods

There are several methods available:

  • #Use Intel graphics only - saves power, because NVIDIA GPU will be completely powered off.
  • #Use NVIDIA graphics only - gives more performance than Intel graphics, but drains more battery (which is not welcome for mobile devices).
  • Using both (use NVIDIA GPU when need and power it off to save power when not needed):
    • #Using optimus-manager - an unofficial implementation of Nvidia's nvidia-prime for Arch Linux. Due to its simplicity to use without compromising performance, it should be default choice for majority of users.
    • #Using nvidia-xrun - run separate X session on different TTY with NVIDIA graphics.
    • #Using Bumblebee - provides Windows-like functionality by allowing to run selected applications with NVIDIA graphics while using Intel graphics for everything else. Has significant performance issues and does not support Vulkan.
    • #Using nouveau - offers poorer performance (compared to the proprietary NVIDIA driver) and may cause issues with sleep and hibernate. Does not work with latest NVIDIA GPUs.

Use Intel graphics only

If you only care to use a certain GPU without switching, check the options in your system's BIOS. There should be an option to disable one of the cards. Some laptops only allow disabling of the discrete card, or vice-versa, but it is worth checking if you only plan to use just one of the cards.

If your BIOS does not allow to disable Nvidia graphics, you can disable it from the Linux itself. See Hybrid graphics#Fully Power Down Discrete GPU.

Use NVIDIA graphics only

The proprietary NVIDIA driver does not support dynamic switching like the nouveau driver (meaning it can only use the NVIDIA device). It also has notable screen-tearing issues that NVIDIA recognizes but has not fixed, unless you are using x.org > 1.19 and enable prime sync, see [1]. However, it does allow use of the discrete GPU and has (as of January 2017) a marked edge in performance over the nouveau driver.

First, install the NVIDIA driver and xorg-xrandr. Then, configure xorg.conf. You will need to know the PCI address of the NVIDIA card, which you can find by issuing

$ lspci | egrep 'VGA|3D'

The PCI address is the first 7 characters of the line that mentions NVIDIA. It will look something like 01:00.0. In the xorg.conf, you will need to format it as #:#:# while converting hexadecimal numbers to decimal numbers; e.g. 01:00.0 would be formatted as 1:0:0.

Note: On some setups this setup breaks automatic detection of the values of the display by the nvidia driver through the EDID file. As a work-around see #Resolution, screen scan wrong. EDID errors in Xorg.log.

If X.Org X server version 1.17.2 or higher is installed ([2])

/etc/X11/xorg.conf
Section "Module"
    Load "modesetting"
EndSection

Section "Device"
    Identifier "nvidia"
    Driver "nvidia"
    BusID "PCI:<BusID for NVIDIA device here>"
    Option "AllowEmptyInitialConfiguration"
EndSection

Next, add the following two lines to the beginning of your ~/.xinitrc:

~/.xinitrc
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto

Now reboot to load the drivers, and X should start.

If your display dpi is not correct add the following line:

xrandr --dpi 96

If you get a black screen when starting X, make sure that there are no ampersands after the two xrandr commands in ~/.xinitrc. If there are ampersands, it seems that the window manager can run before the xrandr commands finish executing, leading to a black screen.

Display managers

If you are using a display manager then you will need to create or edit a display setup script for your display manager instead of using ~/.xinitrc.

LightDM

For the LightDM display manager:

/etc/lightdm/display_setup.sh
#!/bin/sh
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto

Make the script executable:

# chmod +x /etc/lightdm/display_setup.sh

Now configure lightdm to run the script by editing the [Seat:*] section in /etc/lightdm/lightdm.conf:

/etc/lightdm/lightdm.conf
[Seat:*]
display-setup-script=/etc/lightdm/display_setup.sh

Now reboot and your display manager should start.

SDDM

For the SDDM display manager (SDDM is the default DM for KDE):

/usr/share/sddm/scripts/Xsetup
xrandr --setprovideroutputsource modesetting NVIDIA-0
xrandr --auto

GDM

For the GDM display manager create two new .desktop files:

/usr/share/gdm/greeter/autostart/optimus.desktop
/etc/xdg/autostart/optimus.desktop
[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 use X as default backend.

Checking 3D

You can check if the NVIDIA graphics are being used by installing mesa-demos and running

$ glxinfo | grep NVIDIA

Further Information

For more information, look at NVIDIA's official page on the topic [3].

Troubleshooting

Tango-edit-clear.pngThis article or section needs language, wiki syntax or style improvements. See Help:Style for reference.Tango-edit-clear.png

Reason: If this is relevant only for #Use NVIDIA graphics only, it should be a subsection. Otherwise it should be the last section on the page. (Discuss in Talk:NVIDIA Optimus#)

Tearing/Broken VSync

This requires xorg-server 1.19 or higher, linux kernel 4.5 or higher, and nvidia 370.23 or higher. Then enable DRM kernel mode setting, which will in turn enable the PRIME synchronization and fix the tearing.

You can read the official forum thread for details.

Failed to initialize the NVIDIA GPU at PCI:1:0:0 (GPU fallen off the bus / RmInitAdapter failed!)

Add rcutree.rcu_idle_gp_delay=1 to the kernel parameters. Original topic can be found in [4] and [5].

Resolution, screen scan wrong. EDID errors in Xorg.log

This is due to the NVIDIA driver not detecting the EDID for the display. You need to manually specify the path to an EDID file or provide the same information in a similar way.

To provide the path to the EDID file edit the Device Section for the NVIDIA card in Xorg.conf, adding these lines and changing parts to reflect your own system:

/etc/X11/xorg.conf
Section "Device"
       	Option		"ConnectedMonitor" "CRT-0"
       	Option		"CustomEDID" "CRT-0:/sys/class/drm/card0-LVDS-1/edid"
	Option		"IgnoreEDID" "false"
	Option		"UseEDID" "true"
EndSection

If Xorg wont start try swapping out all references of CRT to DFB. card0 is the identifier for the intel card to which the display is connected via LVDS. The edid binary is in this directory. If the hardware arrangement is different, the value for CustomEDID might vary but yet this has to be confirmed. The path will start in any case with /sys/class/drm.

Alternatively you can generate your edid with tools like read-edid and point the driver to this file. Even modelines can be used, but then be sure to change "UseEDID" and "IgnoreEDID".

Wrong resolution without EDID errors

Using nvidia-xconfig, incorrect information might be generated in Xorg.conf and in particular wrong monitor refresh rates that restruct the possible resolutions. Try commenting out the HorizSync/VertRefresh lines. If this helps, you can probably also remove everything else not mentioned in this article.

Lockup issue (lspci hangs)

Symptoms: lspci hangs, system suspend fails, shutdown hangs, optirun hangs.

Applies to: newer laptops with GTX 965M or alike when bbswitch (e.g. via Bumblebee) or nouveau is in use.

When the dGPU power resource is turned on, it may fail to do so and hang in ACPI code (kernel bug 156341).

For known model-specific workarounds, see this issue. In other cases you can try to boot with acpi_osi="!Windows 2015" or acpi_osi=! acpi_osi="Windows 2009" added to your Kernel parameters. (Consider reporting your laptop to that issue.)

No screens found on a laptop/NVIDIA Optimus

Check if $ lspci | grep VGA outputs something similar to:

00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02)
01:00.0 VGA compatible controller: nVidia Corporation Device 0df4 (rev a1)

NVIDIA drivers now offer Optimus support since 319.12 Beta [6] with kernels above and including 3.9.

Another solution is to install the Intel driver to handle the screens, then if you want 3D software you should run them through Bumblebee to tell them to use the NVIDIA card.

Use switchable graphics

Using nouveau

See PRIME for graphics switching and nouveau for open-source NVIDIA driver.

Using Bumblebee

See Bumblebee.

Using nvidia-xrun

See nvidia-xrun.

Using optimus-manager

Optimus-manager is one of the easiest solutions for graphics switching between Nvidia and Intel with a single command. Graphical systray applet is also available.

Installation

Install required NVIDIA driver and optimus-managerAUR. Optionally install bbswitch for power saving and optimus-manager-qtAUR for system tray applet.

Also start and enable optimus-manager.service.

Usage

Note: Switching graphics will log you out automatically. Log in again to use selected graphics.

Use below commands to switch graphics:

$ optimus-manager --switch intel    # Use Intel graphics
$ optimus-manager --switch nvidia   # Use NVIDIA graphics
$ optimus-manager --switch auto     # Switch to different graphics (from what is used now)

Also specify which graphics to use on boot:

$ optimus-manager --set-startup intel
$ optimus-manager --set-startup nvidia

For more information and troubleshooting, see upstream documentation.