Intel Desktop Board D945GRW KD945GRWLKPAK10 ユーザーズマニュアル

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KD945GRWLKPAK10
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Product Description 
 39 
1.13.1.1 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 
Processor 
States 
 
Device States 
Targeted System  
Power 
(Note 1)
 
G0 – working 
state 
S0 – working 
C0 – working 
D0 – working state. 
Full power > 30 W 
G1 – sleeping 
state 
S1 – Processor 
stopped 
C1 – stop 
grant 
D1, D2, D3 – device 
specification 
specific. 
5 W < power < 52.5 W 
G1 – sleeping 
state 
S3 – Suspend to 
RAM.  Context 
saved to RAM. 
No power 
D3 – no power 
except for wake-up 
logic. 
Power < 5 W  
(Note 2)
 
G1 – sleeping 
state 
S4 – Suspend to 
disk.  Context 
saved to disk. 
No power 
D3 – no power 
except for wake-up 
logic. 
Power < 5 W  
(Note 2)
 
G2/S5 
S5 – Soft off.  
Context not saved.  
Cold boot is 
required. 
No power 
D3 – no power 
except for wake-up 
logic. 
Power < 5 W  
(Note 2)
 
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. 
No power to the system.  
Service can be 
performed safely. 
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. 
1.13.1.2 One-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 W (or 
less) in S5 (Standby) mode.  One-Watt operation applies only to the S5 state when the computer is 
turned off, but still connected to AC power.  One-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.