On Tue, Nov 02, 2021 at 12:26:15PM -0600, Theo de Raadt wrote: > acpicpu0 at acpi0: C2(200@148 mwait.1@0x33), C1(1000@1 mwait.1), PSS > > Which means when the idle loop calls the "mwait" instruction, the cpu > will 'instantly' slow down, until an interrupt happens. And thus, save > power. That is how modern cpus work.
I've been running "apmd -A" on all the incarnations of my home server since as long as I can remember (15+ years). If I understand the above correctly, manipulating hw.setperf is in general not the best way to save power on modern CPUs, which would mean running "apmd -A" is not useful anymore on such systems. Is my understanding correct? -- Jurjen Oskam
