Power States And Targeted System Power - Intel BLKD945GCCR Specification

Intel Desktop Board D945GCCR Technical Product Specification
1.11.1.1 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 as a whole into a
low-power state.
Table 7 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 7. Power States and Targeted System Power
Global States Sleeping States
G0 – working S0 – working
state
G1 – sleeping S1 – Processor
state stopped
G1 – sleeping S3 – Suspend to
state RAM. Context
saved to RAM.
G1 – sleeping S4 – Suspend to
state disk. Context
saved to disk.
G2/S5 S5 – Soft off.
Context not saved.
Cold boot is
required.
G3 – No power to the
mechanical off system.
AC power is
disconnected
from the
computer.
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.
1.11.1.2 Two-Watt Standby
In 2001, the U.S. government issued an executive order requiring a reduction in
power for appliances and personal computers. This board meets that requirement by
operating at 1.5 W (or less) in S5 (Standby) mode. Two-Watt operation applies only
to the S5 state when the computer is turned off, but still connected to AC power.
Two-Watt operation does not apply to the S3 (Suspend to RAM) or S4 (Suspend to
disk) states. Newer energy-efficient power supplies using less than 0.5 W (in Standby
mode) may also be needed to achieve this goal.
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Processor
States Device States
C0 – working D0 – working state.
C1 – stop D1, D2, D3 – device
grant specification
specific.
No power D3 – no power
except for wake-up
logic.
No power D3 – no power
except for wake-up
logic.
No power D3 – no power
except for wake-up
logic.
No power D3 – no power for
wake-up logic,
except when
provided by battery
or external source.
Targeted System
Power (Note 1)
Full power > 30 W
5 W < power < 52.5 W
Power < 5 W (Note 2)
Power < 5 W (Note 2)
Power < 5 W (Note 2)
No power to the system.
Service can be
performed safely.