User Manual

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2.14.1.1 System States and Power States
Under ACPI, the operating system directs all system and device power state transitions. The
operating system puts devices in and out of low-power states based on user preferences and
knowledge of how devices are being used by applications. Devices that are not being used can be
turned off. The operating system uses information from applications and user settings to put the
system into a low-power state.
Table 4 lists the power states supported by the board along with the associated system power
targets. See the ACPI specification for a complete description of the various system and power
states.
Table 4. Power States and Targeted System Power
Global States
Sleeping States
Processor
States
Device States
G0 – working state
S0 – working
C0 – working
D0 – working state.
G1 – sleeping state
S3 – Suspend to RAM.
Context saved to RAM.
No power
D3 – no power except for wake-up
logic.
G1 – sleeping state
S4 – Suspend to disk.
Context saved to disk.
No power
D3 – no power except for wake-up
logic.
G2/S5
S5 – Soft off. Context not
saved. Cold boot is required.
No power
D3 – no power except for wake-up
logic.
G3 – mechanical off
AC power is disconnected
from the computer.
No power to the system.
No power
D3 – no power for wake-up logic,
except when provided by battery
or external source.
Notes:
1. Total system power is dependent on the system configuration, including add-in boards and peripherals powered by
the system chassis’ power supply.
2. Dependent on the standby power consumption of wake-up devices used in the system.