Intel Integrated GPU gone after Ubuntu NVidia

This is NOT about my NVidia 4090 disappearing when using the Intel Integrated CPU. It is the opposite. My Ubuntu desktop shouldn’t need to consume 11% of my precious 4090 memory when I have a perfectly good Intel. I want to use the 4090 for AI. Under windows both GPU’s appear. On Ubuntu when I installed the NVidia drivers my Intel integrated GPU no longer appears and I have to plug my monitor into the 4090.

sudo prime-select intel
Error: no integrated GPU detected.

This is a matter of configuration of your linux (Ubuntu) OS. You have options to address this at driver install time if you use the runfile install method, and you can also directly modify your GUI/GDM configuration to switch the display to the intel device.

If it were me, the way I would do it is to first establish proper/desired operation of the Intel Integrated GPU, then install the 4090, then use the runfile install method, deselect the option to install the graphical libraries, and select no if prompted to update any X configuration files. I probably won’t be able to give you recipes for every possible approach here, but you can find many forum threads that discuss how to steer your GUI display to one GPU or another.

There are also motherboards that make this impossible or difficult. They will detect the presence of a GPU in a PCIE slot, and will disable the onboard graphics in that case. In some cases, you can modify this behavior in the System BIOS, in other cases, you have no control over this behavior. You can use the lspci tool to determine if the intel integrated GPU is “present” when the 4090 is plugged in. (It’s quite possible the error you reported is due to this kind of behavior.)

Thanks. The proper operation of the Intel was working with the physically installed 4090. It was only when I installed the driver that I then had problems.
I don’t recall but perhaps I didn’t know better to say no to graphical libraries thinking it would take over my display.

Now the question is how to repair this. If I reinstall and say “no” will it undo any X config stuff? Do I need to uninstall and will that put things back?

As far as the BIOS issue goes the Intel GPU was present and working with the 4090 plugged in. It was the driver install but as you said perhaps I answered Y to some Xorg thing.

NOTE: It is not just that it took over display duties. It also is in some way hiding the existence of the integrated GPU which doesn’t happen on Windows.

I don’t know if you installed using the package manager method or the runfile installer method. In any event, I’m not sure an uninstall will fix things, because the nature of supporting the GL stack and X stack involves overwriting files. I think the way to repair the intel graphics is to use a method to reinstall the intel graphics (driver). You can also try uninstalling the GPU driver to see if that works.

I don’t have a recipe and probably won’t be able to respond to recipe questions. If all else fails, then the final option is to reinstall the OS.