Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 11-05-2007, Installation Manual

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Power Management
Power management is especially important on laptop computers, but is also useful on
other systems. Two technologies are available: APM (advanced power management)
and ACPI (advanced configuration and power interface). In addition to these, it is also
possible to control CPU frequency scaling to save power or decrease noise. These options
can be configured manually or using a special YaST module.
►zseries: The features and hardware described in this chapter do not exist on IBM
System z, making this chapter irrelevant for these platforms. ◄
Unlike APM, which was previously used on laptops for power management only, the
hardware information and configuration tool ACPI is available on all modern computers
(laptops, desktops, and servers). All power management technologies require suitable
hardware and BIOS routines. Most laptops and many modern desktops and servers
meet these requirements.
APM had been used in many older computers. Because APM largely consists of a
function set implemented in the BIOS, the level of APM support may vary depending
on the hardware. This is even more true of ACPI, which is even more complex. For
this reason, it is virtually impossible to recommend one over the other. Simply test the
various procedures on your hardware then select the technology that is best supported.
IMPORTANT: Power Management for AMD64 Processors
AMD64 processors with a 64-bit kernel only support ACPI.
Power Management 503