---
name: "hwpstate_intel"
section: "4"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/hwpstate_intel"
---

# hwpstate\_intel(4)

Intel Speed Shift Technology driver

## 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)](/est/4.md). 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)](/sysctl/8.md) 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)](/cpufreq/4.md) *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 ⟨*scottph@FreeBSD.org*⟩.