Runtime Power Management, v 1.0

Power Management Scheme

EIST will function only if the operating system is using an adaptive power management scheme. The fol-

lowing table shows the relationship between power scheme and the control policy used.

For more information about processor performance control, go to:

http://www.microsoft.com/whdc/system/pnppwr/powermgmt/ProcPerfCtrl.mspx

Power Scheme - Adaptive or Not

An adaptive power scheme allows the operating system to dynamically adjust performance of a processor

(frequency and voltage) according to the amount of processor usage. You can determine whether a

power management scheme is adaptive. If a power management scheme has not been modified, it will

have the default processor performance control policy. However, a modified power scheme will not pro-

vide external notification regarding its current control policy.

To verify processor performance control policy, perform the following steps:

1. Click Start > Run.

2. Type CMD.

3. Type powercfg /query.

The system displays the current power configuration. Processor Throttle <AC> and Processor

Throttle <DC> indicate which control policy is implemented when the system is using AC power or bat-

tery power.

Power Scheme AC Power DC Power

Home/Office Desk None Adaptive

Portable/Laptop Adaptive Adaptive

Presentation Adaptive Degrade

Always On None None

Minimal Power Management Adaptive Adaptive

Max Battery Adaptive Degrade