NAME
hwpstate_intel – Intel Speed Shift Technology driver
SYNOPSIS
To compile this driver into your kernel place the following line in your kernel configuration file:
device cpufreq
DESCRIPTION
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.
SEE ALSO
cpufreq(4) Intel 64 and IA-32 Architectures Software Developer Manuals, http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html.
AUTHORS
This manual page was written by D Scott Phillips ⟨[email protected]⟩.