I'm trying to optimise the power management on my Dell XPS 15 laptop, whose current consumption is approximately equivalent to the output of a midsized nuclear power plant.

I would therefore like to ensure that the hybrid graphics (Optimus) feature works as intended, and shuts off the dGPU when not in use. Do I still need to use Bumblebee and bbswitch to accomplish this, or has Ubuntu (and the kernel) advanced to the point where it's handled natively? I see that prime-select allows choosing one of the graphics processors or --on-demand .

System details: