Nvidia driver, default configuration, "Use dedicated card option" for app triggers software acceleration

[Didier Roche-Tolomelli]

Fresh install of 20.04 LTS with nvidia binary driver from our archive. (dual Intel/Nvidia setup)

No setting change has been done. The card supports "On demand".

Tested with Firefox (about:support) and Chrome (config:cpu). Both are showing the same result:
- default launch -> Intel drive, OK
GL_VENDOR Intel
GL_RENDERER Mesa Intel(R) UHD Graphics 630 (CFL GT2)
GL_VERSION 4.6 (Core Profile) Mesa 20.0.4
- select use dedicated card -> Sofware acceleration! KO
GL_VENDOR Google Inc.
GL_RENDERER Google SwiftShader
GL_VERSION OpenGL ES 3.0 SwiftShader 4.1.0.7

Selecting the option for performance though is worse than not selecting it with our default configuration.

If you open nvidia-settings, you have only one tab available (which is showing Performance mode), which is misleading because this is not the mode you are in. Note that you not on On Demand mode either as selecting it + reboot restores a an expected behavior (multiple tabs in nvidia-settings).

For completeness, here are the other settings:

* On Demand (manually selected): OK
Right click menu option shows Use dedicated card card option: OK
- default launch -> Intel drive, OK
- select use dedicated card -> Nvidia, OK

* Power saving mode (manually selected): OK
- default launch -> Intel drive, OK

* Performance mode (manually selected, meaning choose another option to change the default and selecting it back): KO
Right click menu option shows Use dedicated card card option! KO
- default launch -> Nvidia, OK
- select use dedicated card -> Nvidia, OK, but this option shouldn’t be present.
Reported this one as bug #1876049

2 additional things:
- It would be great the default to be either Performance mode (real one) or On Demand for supported card (nvidia-settings has the option only if this is supported AFAIK, so it would be good to default dynamically to this one. Filed as bug #1876051
- It would be great to have a way to pin an application with "Use dedicated card". bug #1876050

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: gnome-shell 3.36.1-5ubuntu1
ProcVersionSignature: Ubuntu 5.4.0-28.32-generic 5.4.30
Uname: Linux 5.4.0-28-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Thu Apr 30 09:22:04 2020
DisplayManager: gdm3
InstallationDate: Installed on 2020-04-24 (5 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
RelatedPackageVersions: mutter-common 3.36.1-3ubuntu3
SourcePackage: gnome-shell
UpgradeStatus: No upgrade log present (probably fresh install)