What is the purpose of prime-select?

Graphics / Linux Linux
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1

What is the purpose of prime-select?

Is the purpose:

  • To set which device, Intel or NVidia should control my monitor; or
  • To set which device, Intel or NVidia should control my monitor, and DISABLE the other device, which has nothing to do with the video selection from working, and doing it in such a way that few people would be able to figure out why their NVidia device, being used solely for AI, stopped working?

After upgrading my NVidia drivers and CUDA, I had audio problems with my Intel Integrated GPU so I ran NVidia “prime-select intel” and rebooted. The audio works but I had no expensive 4090 anymore. Why? What does selecting the device for the sole purpose of running my monitor have to do with letting my 4090 continue to operate as a computing device? Eventually I figured out it had blacklisted my nvidia drivers rendering the device inoperable. Again, what is the purpose of this utility and why does it need to kill my nvidia just to get my video/audio to work?

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FYI, I don’t know enough about DRM Direct “RENDERING” to know whether it was indeed correct to blacklist the DRM driver and modeset module. If I am not rendering does the DRM driver get in the way in terms of resources or performance for leaving my 4090 100% for AI purposes?

But the utility ALSO disables the entire device.