Comment 133 for bug 1778011

After spending some more time with this, I can confirm that this is definitely a regression. Both nouveau and the old bbswitch based method in 16.04 were able to power off the nvidia card successfully when not in use. The current implementation of prime-select in 18.04 doesn't do that. It may be that this is card or ACPI specific, but my hardware is fairly old (2012 ivybridge with kepler GPU), and it doesn't work for it.