PwrTest Disk Scenario

The PwrTest Disk Scenario monitors disk idle statistics and spin-down events.

This scenario is primarily used for Windows 7 hard disk power activity, subsequent versions of Windows use a different mechanism for tracking disk idle that is not currently supported by Pwrtest. For versions of Windows newer than Windows 7, use the Windows Performance Toolkit (WPT). The WPT includes the Windows Performance Recorder (WPR) that you can use to trace the kernel-mode power provider and the Windows Performance Analyzer (WPA) that can show the power framework (PoFx) device statistics and can graph the transitions afterward.

This scenario does not work for all types of disks or controllers because not all storage drivers register for idle detection. See Handling PnP Start in a Storage Class Driver for more information.


pwrtest /disk  [/t:n] [/?] 

Specifies the total time (in minutes) for the scenario to run (the default value for n is 30 minutes).


pwrtest /disk /t:60
pwrtest /disk

XML log file output


The following table describes the XML elements that appear in the log file.

Element Description

Contains all the different disk idle events. Only one <DeviceIdleEvents> element per PwrTest log file.


Time stamp of any given event.


Identifies which physical disk is this event for.


Device instance path.


Device add or remove event.


DeviceRemoved or DeviceDetected.


Disk timeouts change event.


New disk spin-down timeout.


New disk idle ignore threshold.


Functional device object.


Physical device object


The number of times the device driver called PoSetDeviceBusy during the period.


The number of times the device driver call PoSetDeviceBusy total.


What numeric state is the idle state.


The current numeric power state.


Timeout (in seconds).


The number of seconds of non-idle time to ignore


The accrued idle time during the period.


The total idle time that has accrued.


String that describes what happened during the period.

Related topics

PwrTest Syntax