On Tue, Mar 10, 2020 at 9:24 AM Theron <theron.tar...@gmail.com> wrote: > I had previously used powerd to let the CPU underclock to 700MHz when > idle. Now, I've lost all control over CPU frequency (either by powerd > or by sysctl) since there is some in-kernel cpufreq driver which I can't > figure out how to disable.
It's hwpstate_intel(4). You can add 'hint.hwpstate_intel.0.disabled="1"' in loader.conf or device.hints to disable and use est(4), if you prefer. The idea of the device is that hardware can do a better job managing the frequency / power states rapidly than daemons like powerd. But if you like powerd/est, feel free to disable it. Future models of Intel CPU may not provide est(4). If you leave it enabled, you can control the energy efficiency / performance trade-off of hwpstate_intel on a per-core basis (or per-package, if not disabled and hardware supports package-level control) with 'dev.hwpstate_intel.<cpu>.epp=0-100' (sysctl or tunable); the CPU uses this knob to control how biased it is towards low frequency states. 100 is most efficient, 0 is most performant. The default is 50. Best, Conrad _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
