cpu4

Usage

Overview

Several processor models have additional features that extend their base functionality, such as power and frequency control or thermal monitoring.

The sysctl(2) hw.cpuspeed returns the current operating frequency of the processor, though on some processors this value may be only an approximation. If possible, speed may be adjusted by altering hw.setperf from 0 to 100, representing percentage of maximum speed.

There are several possible implementations for speed adjustment, all transparent to the user:

EST

Enhanced SpeedStep found on Intel and VIA processors, offering frequency scaling with numerous positions.

PowerNow

Found on various AMD processors. It currently only supports a limited set of models in the K8 families.

The presence of extended instruction sets can be determined by the sysctl machdep:

xcrypt

Supports the VIA AES encryption instruction set.

The sysctl hw.sensors returns the current temperature reported by the processor.