Specification Sheet

Power Management

Intel

Xeon

Processor E5-1600/E5-2600/E5-4600 v2 Product Families 97

Datasheet Volume One of Two

4.2.5.1 Package C0

The normal operating state for the processor. The processor remains in the normal

state when at least one of its cores is in the C0 or C1 state or when the platform has

not granted permission to the processor to go into a low power state. Individual cores

may be in lower power idle states while the package is in C0.

4.2.5.2 Package C1/C1E

No additional power reduction actions are taken in the package C1 state. However, if

the C1E substate is enabled, the processor automatically transitions to the lowest

supported core clock frequency, followed by a reduction in voltage. Autonomous power

reduction actions which are based on idle timers, can trigger depending on the activity

in the system.

The package enters the C1 low power state when:

• At least one core is in the C1 state.

• The other cores are in a C1 or lower power state.

The package enters the C1E state when:

• All cores have directly requested C1E via MWAIT(C1) with a C1E sub-state hint.

• All cores are in a power state lower that C1/C1E but the package low power state is

limite

d to C1/C1E via the PMG_CST_CONFIG_CONTROL MSR.

• All cores have requested C1 using HLT or MWAIT(C1) and C1E auto-promotion is

enabled in POW

ER_CTL.

No notification to the system occurs upon entry to C1/C1E.

Figure

4-3. Package C-State Entry and Exit

C6C3