System Overview 1-11! CAUTIONOnly when the AC power is disconnected is the system completelyoff.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 maintaincoherency.! s4: Hibernate or Save to Disk.The memory and machine state are saved to disk. Pressing the power button orother wakeup event restores the system state from the disk and resumes normaloperation. This assumes that no hardware changes have been made to the systemwhile it was off.! s5: Soft off.Only the RTC section of the chipset and the BMC are running in this state.AC Link ModeThe AC link mode allows the system to monitor its AC input power so that when theAC 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."
