Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
Processor power management technologies are defined in the ACPI specification and are divided into two categories or states:
Power performance states (ACPI P states)
P-states provide a way to scale the frequency and voltage at which the processor runs so as to reduce the power consumption of the CPU. The number of available P-states can be different for each model of CPU, even those from the same family.
Processor idle sleep states (ACPI C states)
C-states are states when the CPU has reduced or turned off selected functions. Different processors support different numbers of C-states in which various parts of the CPU are turned off. To better understand the C-states that are supported and exposed, contact the CPU vendor. Generally, higher C-states turn off more parts of the CPU, which significantly reduce power consumption. Processors may have deeper C-states that are not exposed to the operating system.