In 8 hours it uses 20% of the battery. When Windows or Mac are put to sleep, the damn things can sleep for a week! This is the case with Linux on multiple laptops.
Is there some kind of manipulation going by ring -1 that detects Linux is running? Is Linux not respecting some procedure and kissing a step?
This is the answer.
Proprietary firmware. Fuck Intel.
Laptops with AMD chips are not necessarily better in this regard.
From my anecdotal experience with an HP laptop (from work), with an AMD 7840HS, the blame is often also with the system integrator. That one has a bug in the power management system, where if you plug the charger in during sleep, the power state gets locked to some very low power sleep mode, until you either reboot, or plug the charger in while it’s not asleep.
HP doesn’t want to look at this because they don’t support Linux, meanwhile AMD kernel devs claim that this is probably a BMC bug so they can’t fix it. Whatever the real culprit is in my case, the BMC can do so much these days that it wouldn’t surprise me if a lot of sleep issues are due to bad firmware.
Either way, system integrators like HP refusing to support Linux is in part what allows Intel and AMD to ignore a lot of Linux-specific bugs. SIs have a lot of manpower to help diagnose and fix them, and they have leverage when reporting bugs to CPU manufacturers.