Datasheet

Power Management
18 Datasheet
3 Power Management
Processor supports fine grain power management by having several partitions of
voltage islands created through on-die power switches. The Intel® Smart Power
Technology (Intel® SPT) software determines the most power efficient state for the
platform at any given point in time and then provides guidance to turn ON or OFF
different voltage islands on processor. For the scenario where Intel® SPT has directed
the processor to go into an Intel® SIT idle mode, the processor waits for all partitions
with shared voltage to reach a safe point and then turns them off.
3.1 Processor Core Low Power Features
When the processor core is idle, low-power idle states (C-states) are used to save
power. More power savings actions are taken for numerically higher C-states.
However, higher C-states have longer exit and entry latencies.
Figure 3-1
shows the thread low power states. Figure 3-2 shows the package low
power states.
Note: STPCLK#, DPSLP#, and DPRSTP are internal signals only.