Ubuntu 20.04 LTS - llvmpipe (LLVM 10.0.0, 256 bits) used instead of NVIDIA graphic card or INTEL internal graphic shared card

Question

I'm using :

ubuntu 20.04, gnome 3.36.4, NVIDIA® GeForce® GTX 1050 and Intel UHD Graphics 630.

I 've installed Nvidia-driver-435 till about a month ago and now Nvidia-driver-450 but the graphic card that I can see on gnome information GUI is set as llvmpipe (LLVM 10.0.0, 256 bits) instead of nvidia graphics o Intelgraphic card.

I 'm not able to adjust screen resolution setting that is fixed is only 3840x2160 (16:9) and I cannot even use Intel UHD Graphics 630.

I 've tried also using noveau drivers some week ago but also in that case the screen resolution was fixed to 3840x2160 (16:9)

Input:

:~$ prime-select query  

Output:

nvidia

Also if I want to switch to intel internal card I can see on gnome customizzation info gui is set as llvmpipe

Input:

:~$ sudo prime-select intel

Output:

Info: selecting the intel profile

gnome infos about graphic card

Input:

:~$ DRI_PRIME=0 glxinfo | grep "OpenGL renderer" 

Output:

OpenGL renderer string: llvmpipe (LLVM 10.0.0, 256 bits)

Input:

:~$ DRI_PRIME=1 glxinfo | grep "OpenGL renderer"

Output:

OpenGL renderer string: llvmpipe (LLVM 10.0.0, 256 bits)

Input:

:~$ glxinfo | grep renderer

Output:

    GLX_MESA_multithread_makecurrent, GLX_MESA_query_renderer, 
    GLX_EXT_visual_rating, GLX_MESA_copy_sub_buffer, GLX_MESA_query_renderer, 
Extended renderer info (GLX_MESA_query_renderer):
OpenGL renderer string: llvmpipe (LLVM 10.0.0, 256 bits)

Input:

:~$ nvidia-smi

Output:

NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running.

Answer 1

Googling for a solution I come up with this solution Ubuntu 20.04 Intel HD 615: No Brightness control or no Boot Considering that I also do not have brightness controll I've investigated in my grub settings, in my /etc/default/grub configuration.

So I found that I had:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX="nomodeset"

I've tried to change with

GRUB_CMDLINE_LINUX_DEFAULT=""
GRUB_CMDLINE_LINUX=""

and then update the GRUB config file with

sudo update-grub

and now finally I 've got my Mesa Intel® UHD Graphics 630 (CFL GT2) in the info gnome panel. Now I've also the possibility to switch to NVIDIA card too. The problem of use of llvmpipe (LLVM 10.0.0, 256 bits) was caused by a wrong setting "nomodeset" in my grub configuration.

Answer 2

I also have both integrated GPU and dedicated GPU.

With export MESA_D3D12_DEFAULT_ADAPTER_NAME=INTEL and

export MESA_D3D12_DEFAULT_ADAPTER_NAME=NVIDIA,

I can use one of the GPU.