Datasheet

Power Management
40 Datasheet
4.1.7 Interface State Combinations
4.2 Processor Core Power Management
While executing code, Enhanced Intel SpeedStep Technology optimizes the processors
frequency and core voltage based on workload. Each frequency and voltage operating
point is defined by ACPI as a P-state. When the processor is not executing code, it is
idle. A low-power idle state is defined by ACPI as a C-state. In general, lower power
C-states have longer entry and exit latencies.
Table 4-11.G, S and C State Combinations
Global
(G) State
Sleep
(S) State
Processor
Core
(C) State
Processor
State
System Clocks Description
G0 S0 C0 Full On On Full On
G0 S0 C1/C1E Auto-Halt On Auto-Halt
G0 S0 C3 Deep Sleep On Deep Sleep
G0 S0 C6 Deep Power
Down
On Deep Power Down
G1 S3 Power off Off, except RTC Suspend to RAM
G1 S4 Power off Off, except RTC Suspend to Disk
G2 S5 Power off Off, except RTC Soft Off
G3 NA Power off Power off Hard off
Table 4-12.D, S, and C State Combination
Graphics Adapter
(D) State
Sleep (S) State Package (C) State Description
D0 S0 C0 Full On, Displaying
D0 S0 C1/C1E Auto-Halt, Displaying
D0 S0 C3 Deep sleep, Displaying
D0 S0 C6 Deep Power Down,
Displaying
D3 S0 Any Not displaying
D3 S3 N/A Not displaying, Graphics
Core is powered off
D3 S4 N/A Not displaying, suspend to
disk