User vermaden goes into detail about power management on your FreeBSD machine. Vermaden discusses battery wear, CPU settings, Turbo mode, SATA/AHCI power management, suspend & resume, among several other things one should be conscious about regarding power and FreeBSD. See the link below for the full guide.
Time for FreeBSD article covering its power management features. It also applies to FreeBSD Desktop series but its not limited to it. Popular opinion seems to be that FreeBSD is so server oriented that it lacks any power management mechanisms. Nothing more far from the truth. While less important on the desktop (but will still lower your electricity bill) or servers it is desirable to properly configure power management on laptops to so they will have longer battery life and will run more quiet.
I write this as the FreeBSD Handbook does not cover all that information in the 11.13. Power and Resource Management chapter. The FreeBSD on Laptops article part 4. Power Management is from the ancient times of FreeBSD 10.1-RELEASE. There is some information on the FreeBSD Wiki page but parts of it are outdated.
FreeBSD offers many mechanisms in the power management department: ….
Hacker News discussion: https://news.ycombinator.com/item?id=18554649