Comment 0 for bug 1942789

RTD3 is a nvidia GPU feature to support runtime suspend.

On-demand would be a X offloading feature.

They are independent, according to discussion on https://github.com/tseliot/ubuntu-drivers-common/issues/55.

Some parts need to be adjusted, e.g.

```
    # If we are dealing with NVIDIA PRIME, and runtimepm
    # is supported, enable it
    if (os.path.isfile('/run/nvidia_runtimepm_supported') and
        os.path.isfile('/usr/bin/prime-select')):
        print('Trying to select the on-demand PRIME profile')
        try:
            subprocess.call(['prime-select', 'on-demand'])
        except:
            pass

        # Create the override file for gpu-manager
        with open('/etc/u-d-c-nvidia-runtimepm-override', 'w') as f:
            f.write('# File created by ubuntu-drivers\n')
```