LessWatts.org - Saving Power on Intel systems with Linux

Index
PowerTOP
Tickless Idle
Power Policy Manager
Applications Power Management
Processor Power Management

Introduction
EIST
Intel Dynamic Acceleration Technology
Intel Enhanced Deeper Sleep
FAQ
Downloads

Power and Performance Measurement
BLTK
Linux ACPI
ACPICA
Power QoS
Device and Bus Power Management
Display and Graphics Power Saving

Processor Power Management

Enhanced Intel Speedstep Technology (EIST)

The EIST feature supports changing the CPU frequency and voltage at runtime, which provides power savings when high CPU frequency isn’t required.

The cpufreq driver that supports EIST on an Intel processor is acpi-cpufreq, which is available in Linux kernel version 2.6.21 and later. This driver is actively maintained, and new features are added, such as ACPI 3.0 support and Intel Dynamic Acceleration.

The Intel recommended governor in the Linux kernel, cpufreq ondemand, changes the frequency/voltage of the processor at runtime, based on the CPU utilization. This driver is actively maintained and enhanced with new features.