advanced power management (PC) (APM)

The Advanced Power Management(APM) developed by Intel and Microsoft is used to reduce the power consumption of personalcomputers, in particular battery-powered laptops and notebooks. With this power management, the firmware and hardware have direct access to the values for power consumption and can switch hardware components that are not actively involved in the processing to standby mode.

Since input devices such as the keyboard and computer mouse are monitored, as are the interfaces, APM switches the respective component back to normal operation in the event of incoming actions. In terms of functionality, APM only offers simpler controls compared to Advanced Configuration and Power Interface( ACPI).

Operating modes of Power Management (PM)

The operating modes are divided into Hibernation, which is activated when the battery voltage drops or after a preset period of time during which no operation is performed, the Suspend modes Suspend-to-Disk and Suspend-to- RAM, and the Wake-up mode. In suspend mode, the devices no longer operate actively, but still pay attention to the wake-up signals.

Power management offers special advantages for battery-powered devices, but is also used for displays as a Display Power Management System( DPMS).