I have a Dell XPS 15 9560 laptop with an Nvidia GTX 1050 graphics card. I just installed Ubuntu 20.04 with nvidia-driver-440.
When I run prime-select intel and reboot, prime-select query prints intel as expected, but powertop shows the NVIDIA GPU running at 100%, and the laptop is hot. The same happens in on-demand mode.
The existing question's accepted answer is for Ubuntu 18.04 and doesn't fix my problem, since sudo tee /proc/acpi/bbswitch <<<OFF returns tee: /proc/acpi/bbswitch: No such file or directory.
How to power off the NVIDIA GPU, using the proprietary driver?