Not using dGPU on linux

[Varun-garg]

• Are you using the latest driver? Yes
• Are you using the latest EVDI version? Tes
• If you are using a DisplayLink device, have you checked 'troubleshooting'
  on DisplayLink's website? Yes
• Is this issue related to evdi/kernel? Yes

• Linux distribution and its version: arch
• Linux kernel version: 6.3.6-zen1-1-zen
• Xorg version (if used): X.Org X Server 1.21.1.8
• Desktop environment in use: gnome
• Nvidia drivers: nvidia-470xx-dkms

I have an amd cpu (without igpu) and an nvidia gpu. my gpu's output port does not connect to any display device. On windows when I use the docking station in the performance monitor, I can see nvidia gpu being used. For instance, when I play a video, not much gets changed in CPU, but nvidia GPU usage spikes up to 60-70% and then stays to about 20%. When I pause it goes back to around 1%.

On Linux the behaviour is very different. When I do some graphics activity like mpv or youtube, nvidia-smi says gpu is idle, and the CPU usage shoots up. There are a lot of DisplayLink threads that process the workload on the CPU I assume.

So the question I have is, if it can use dGPU on Windows, why doesn't it do the same on Linux?