hwpstate_intel4

Usage

Overview

The hwpstate_intel driver provides support for hardware-controlled performance states on Intel platforms, also known as Intel Speed Shift Technology.

Loader tunables

hint.hwpstate_intel.0.disabled

Can be used to disable hwpstate_intel, allowing other compatible drivers to manage performance states, like est(4). Defaults to "0" (enabled).

machdep.hwpstate_pkg_ctrl

Selects between package-level control (the default) and per-core control. "1" selects package-level control and "0" selects core-level control.

Sysctl variables

The following sysctl(8) values are available

dev.hwpstate_intel.%d.%desc

Describes the attached driver

dev.hwpstate_intel.0.%desc: Intel Speed Shift

dev.hwpstate_intel.%d.%driver

Driver in use, always hwpstate_intel.

dev.hwpstate_intel.0.%driver: hwpstate_intel

dev.hwpstate_intel.%d.%parent

The CPU that is exposing these frequencies. For example cpu0.

dev.hwpstate_intel.0.%parent: cpu0

dev.hwpstate_intel.%d.epp

Energy/Performance Preference. Valid values range from 0 to 255. Setting this field conveys a hint to the hardware regarding a preference towards performance (at value 0), energy efficiency (at value 255), or somewhere in between.

dev.hwpstate_intel.0.epp: 0

Compatibility

hwpstate_intel is only found on supported Intel CPUs.