ACPI

The Advanced Configuration and Power Interface (ACPI) aware operating system can place the system into a state where the hard drives spin down, the system fans stop, and all processing is halted. However, in this state the power supply is still on and the processors are still dissipating some power such that the power supply fan and processor fans are still running.

Note: ACPI requires an operating system that supports its feature.

This server system BIOS supports sleep states s0, s1, s4, and s5. However, with future versions of Microsoft Windows 9X that support ACPI, the system BIOS only supports sleep states s0, s1, and s5. With future versions of Microsoft Windows NT that support ACPI, the system BIOS will only support sleep states s0, s1, s4, and s5.

!CAUTION

Only when the AC power is disconnected is the system completely off.

The sleep states are defined as follows:

!s0: Normal running state.

!s1: Processor sleep state.

No context will be lost in this state and the processor caches will maintain coherency.

!s4: Hibernate or Save to Disk.

The memory and machine state are saved to disk. Pressing the power button or other wakeup event restores the system state from the disk and resumes normal operation. This assumes that no hardware changes have been made to the system while it was off.

!s5: Soft off.

Only the RTC section of the chipset and the BMC are running in this state.

AC Link Mode

The AC link mode allows the system to monitor its AC input power so that when the AC input power is lost and then restored the system will return itself to one of three pre- selected settings, listed as follows:

!Power On

!Last State (Factory Default Setting)

!Stay Off.

The AC link mode settings can be changed by running the BIOS Setup Utility (F2). Refer to Chapter 3 "Configuring Your System."

System Overview 1-15

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Intel 5800/120Ld manual AC Link Mode, Acpi