Windows 7: The Power Management Workout!

Andy Malone MVP, MCTCEO / Trainer / ConsultantQuality Training (Scotland) Ltd &Dive Deeper Technology Events EMEASession Code: CLI321

This Session Will Cover:The Need for Green!Processor Developments inc Core Parking TechnologyWindows Power Management Architecture Using Trigger Start Services, Idle Resource Utilisation, Timer CoalescingEnhanced Power Managements Features: Adaptive display Brightness, Low Power Audio, Bluetooth & Network power Enhancements.Enhancing Notebook & Net book Battery LifePlayback Pipeline scalingUsing Group Policies to configure Power & Performance settings.Power Efficiency Diagnostics: Using PowerCFG.exe Drilldown.Conclusions & Q&A

The Need for Green!

The Need for Green!

Increasing number of mobile usersIncreased number of users leaving laptops / PCs on downloading movies, music etcWide Availability of Broadband. Users leaving PCs On-Line for updates, patching etcI’m not paying the bill so users have a don’t Care Mentality.Need to leave systems on for Backup, defragmentation, AV purposes.

We Need to be Smarter!

A Dynamic and Design Scalable Microarchitecture

Increasing Energy Focus on PCs

Increasing Energy CostsPC energy consumption has doubled since 2000

EPA estimates PCs use ~2% of all electricity consumed

Businesses trimming costsIncreased mobile workforceMore home users are thinking “green”

PC on 24/7 is 8% of household power usage

From http://www.energystar.gov/ia/partners/prod_development/revisions/downloads/computer/TierII_Network_Issue_Slides.pdf

Hours/year

Off

Sle

ep

100 -

0 -

50 -

Pow

er

(watt

s)

0 8760

Idle

Activ

e

Green Hardware + software Solutions!

Power Management DevelopmentsPlug and Play, ACPI, On Now

Solutions are a combination of Hardware Architecture & Operating System AdvancesAutomating Internet updates or system-maintenance utilitiesHandling docking changes for mobile usersPreserving network connectionsKeeping presentations onlineExtending mobile battery lifeHandling events for network agents and peripherals.

The Advanced Configuration and Power Interface (ACPI)

Open standard for unified operating system-centric device configuration and power management. Released in 1996, Defines platform-independent interfaces for hardware discovery, configuration, power management and monitoring. Specification is central to Operating System-directed configuration and Power Management (OSPM); a term used to describe a system implementing ACPI.Removes device management responsibilities from legacy firmware interfaces. Standard was originally developed by Intel, Microsoft, and Toshiba, and last published as "Revision 4.0", in June 2009.

Managing Active PowerWindows 7 changes frequency as needed to meet performance needs, minimize power

Enhanced Intel SpeedStep TechnologyReferred to as processor P-States

PCU tunes voltage for given frequency, operating conditions, and silicon characteristics

PCU automatically optimizes operating voltage

Processor Power Control Unit

PLL

Uncore, LLC

Core

Vcc

Freq.

Sensors

Core

Vcc

Freq.

Sensors

Core

Vcc

Freq.

Sensors

Core

Vcc

Freq.

Sensors

PLL

PLL

PLL

PLL

PCU

BCLKVcc

Integrated proprietary microcontrollerShifts control from hardware to embedded firmwareReal time sensors for temperature, current, powerFlexibility enables sophisticated algorithms, tuned for current operating conditions

PowerNow!™ Dashboard

PowerTOP For Open Solaris

Understanding Processor States:Intel Deep Power Down Technology (DPD)

(DPD) is the latest & lowest possible Processor power state. Referred to as “C6” State.In this mode

The processor flushes and disables L2 cacheSaves the state of each core into on-die SRAM memory.Then lowers core voltage close to 0 Volt.Thermal Design Power of dual-core mobile CPUs in this state is 0.3 Watt.

Intel Deep Power Down (DPD)

The process of waking up the CPU from DPD mode is initiated by a chipset.The chipset signals VRM to increase core voltage.The CPU's internal clock is activated and wakes up the CPU. The CPU in its turn resets internal state, restores previously stored state from on-die SRAM, and enables L2 cache. Deep Power Down mode was first introduced in Intel Penryn core.

Understanding Processor Power StatesMode Name What it does CPUs

C0 Operating State CPU fully turned on All CPUs

C1 HaltStops CPU main internal clocks via software; bus interface unit and APIC are kept running at full speed.

486DX4 and above

C1E Enhanced HaltStops CPU main internal clocks via software and reduces CPU voltage; bus interface unit and APIC are kept running at full speed.

All socket 775 CPUs

C1E — Stops all CPU internal clocks. Turion 64, 65-nm Athlon X2 and Phenom CPUs

C2 Stop GrantStops CPU main internal clocks via hardware; bus interface unit and APIC are kept running at full speed.

486DX4 and above

C2 Stop Clock Stops CPU internal and external clocks via hardware

Only 486DX4, Pentium, Pentium MMX, K5, K6, K6-2, K6-III

C2E Extended Stop Grant

Stops CPU main internal clocks via hardware and reduces CPU voltage; bus interface unit and APIC are kept running at full speed.

Core 2 Duo and above (Intel only)

C3 Sleep Stops all CPU internal clocks Pentium II, Athlon and above, but not on Core 2 Duo E4000 and E6000

C3 Deep Sleep Stops all CPU internal and external clocks Pentium II and above, but not on Core 2 Duo E4000 and E6000; Turion 64

C3 AltVID Stops all CPU internal clocks and reduces CPU voltage AMD Turion 64

C4 Deeper Sleep Reduces CPU voltage Pentium M and above, but not on Core 2 Duo E4000 and E6000 series; AMD Turion 64

C4E/C5 Enhanced Deeper Sleep

Reduces CPU voltage even more and turns off the memory cache Core Solo, Core Duo and 45-nm mobile Core 2 Duo only

C6 Deep Power Down Reduces the CPU internal voltage to any value, including 0 V 45-nm mobile Core 2 Duo only

Intel® Core™ Microarchitecture Package C-State Support Example

Active CPU Power

Core Leakage

Core Clock Distribution

Core Clocks and Logic

Uncore Leakage

Uncore Clock Distribution

I/O

Uncore Logic

Core

s (x

N)

All cores in C6 state:Core power to ~0

Intel® Core™ Microarchitecture (Nehalem) Package C-State Support Example

Active CPU Power

Uncore Leakage

Uncore Clock Distribution

I/O

Uncore Logic

All cores in C6 state:Core power to ~0

Package to C6 state:Uncore logic stops toggling

Intel® Core™ Microarchitecture Package C-State Support Example

Active CPU Power

Uncore Leakage

Uncore Clock Distribution

I/O

All cores in C6 state:Core power to ~0

Package to C6 state:Uncore logic stops togglingI/O to lower power state

Intel® Core™ Microarchitecture Package C-State Support Example

All cores in C6 state:Core power to ~0

Package to C6 state:Uncore logic stops togglingI/O to lower power stateUncore clock grids stopped

Active CPU Power

Uncore Leakage

Uncore Clock Distribution

I/O

Substantial reduction inidle CPU power

C6 on Intel® Core™ Microarchitecture

C6 on Intel® Core™ Microarchitecture (Nehalem)

Core 0

Core 1

Core 2

Core 3

Core Power

Time

0

0

0

0

Cores 0, 1, 2, and 3 running applications.

C6 on Intel® Core™ Microarchitecture (Nehalem)

Core 0

Core 1

Core 2

Core 3

Core Power

Time

0

0

0

0

Task completes. No work waiting. OS executes MWAIT(C6) instruction.

C6 on Intel® Core™ Microarchitecture (Nehalem)

Core 0

Core 1

Core 2

Core 3

Core Power

Time

0

0

0

0

Execution stops. Core architectural state saved. Core clocks stopped. Cores 0, 1, and 3 continue execution undisturbed.

C6 on Intel® Core™ Microarchitecture (Nehalem)}

Core 0

Core 1

Core 2

Core 3

Core Power

Time

0

0

0

0

Core power gate turned off. Core voltage goes to 0. Cores 0, 1, and 3 continue execution undisturbed.

C6 on Intel® Core™ Microarchitecture (Nehalem)

Core 0

Core 1

Core 2

Core 3

Core Power

Time

0

0

0

0

Task completes. No work waiting. OS executes MWAIT(C6) instruction. Core 0 enters C6. Cores 1 and 3 continue execution undisturbed.

C6 on Intel® Core™ Microarchitecture (Nehalem)

Core 0

Core 1

Core 2

Core 3

Core Power

Time

0

0

0

0

Interrupt for Core 2 arrives. Core 2 returns to C0, execution resumes at instruction following MWAIT(C6). Cores 1 and 3 continue execution undisturbed.

C6 on Intel® Core™ Microarchitecture (Nehalem)

Core 0

Core 1

Core 2

Core 3

Core Power

Time

0

0

0

0

Core independent C6 on Intel Core Microarchitecture (Nehalem)

Interrupt for Core 0 arrives. Power gate turns on, core clock turns on, core state restored, core resumes execution at instruction following MWAIT(C6). Cores 1, 2, and 3 continue execution undisturbed.

Controlling Sleep States

C State Example

ACPI & On Now Example

Windows Server 2008 R2 Core ParkingWindows Server has added additional support which:

Schedules virtual machines on a single server for density as opposed to dispersionThis allows “park/sleep” cores by putting them in deep C states

BenefitsEnhances Green IT by reducing CPU power consumption

Windows Server 200816 LP Server

Windows Server 2008 R2 Core Parking16 LP Server

Processor is “parked”

Processor is “parked”

Estimated ROI (University of Plymouth)

Windows 7 Power Efficiency

Idle Power Management

Active Power Management

New Self Diagnostics

Improved Local & Remote

Management

Always Available

New Windows 7 Power Improvements Include:

Reduced Power ConsumptionIdle Resource Utilization Trigger Start Services Enhanced Processor Power Management Timer Coalescing Device Power Management Adaptive Display Brightness Low-Power Audio Bluetooth Power Improvements

Networking Power Improvements Enhanced User Experiences Greater Enterprise Power Management Power Efficiency Diagnostics Group Policy Windows Management Instrumentation Power Policy

And There’s More:

Frequent Idle Activity

Specific Windows 7 improvementsEliminate TCP DPC (Differential Power Comparison) timer on every system timer interruptReduce frequency of USB driver maintenance timersIntelligent Timer Tick Distribution (ITTD)Timer Coalescing

Goal = Eliminate idle activity in drivers and applications

Target average idle period greater than 100ms

Timer CoalescingPlatform energy efficiency can be improved by extending idle periods

New timer coalescing API enables callers to specify a tolerance for due timeEnables the kernel to expire multiple timers at the same time

Extensions should integrate with Windows 7 API/DDI

Windows 7

Timer tick15.6 ms

Periodic Timer Events

Vista

Power Architecture

Managing Background Processes

System Management

Device management

System Maintenance

Windows Service Control Manager (SCM)

Windows Task Scheduler

Services and the Service Control ManagerStarts and stops services.Managing services that are running.Maintaining service-related state information.Services can either be

RunningStoppedPaused

The SCM can also notify a service when the machine is entering a sleep state.

Service Control Manager (SCM)

Service Control

Manager (SCM)

Device connect trigger

IP address trigger

Domain trigger

Group Policy (GP) trigger

Custom trigger

Service 1

Subscribed to start on Device Connect

trigger

Service 2Subscribed to

start on Domain join trigger, Stop

on Domain disjoin trigger, and Start

on GP triggerservice 1

Subscribed to start on Device Connect

trigger

Optimizing Services

Windows Task Scheduler

The Task Scheduler:Maintains a database of installed tasksStarts and stops tasks.Manages running tasks.Maintains task-related state information.

Tasks can be:Ready - Running – Queued - Disabled

Windows Task Scheduler – OptimizationTriggers start services allow background processes to start on demand.

The following can improve system efficiency, power consumption, and user experience.

Idle ConditionSetting enables a task to run whenever the system is not actively in use by a user.

Power ConditionSpecifies that the task should be run only when the system is running on AC power

Windows 7 Trigger-Start ServicesMany services were configured to Autostart and wait for rare eventsUBPM enables Trigger-Start services based on environmental changes (On Demand)

Device arrival/removal, IP address change, domain join, etc.Examples

Bluetooth service is started only if a Bluetooth radio is currently attachedBitLocker encryption service started only when new volumes detected

Upbm...huh, What that?The ubpm.dll is a Unified Background Process Manager DLL.

Controlling TriggersMethods of starting triggers include the SC Command or through Task Scheduler. sc qtriggerinfo <SERVICENAME>Configuring a service to trigger-start when the computer acquires its first IP address is similarly easy:sc triggerinfo <SERVICENAME> start/networkon

Trigger Service Bluetooth Example!

The BTHSERV (Bluetooth) Service Dynamically Starts when a Bluetooth

device is Started.

Some Trigger-Start Services In Windows 7Service Name Description Trigger Type

AELookupSvc Processes application compatibility cache requests for applications as they are launched

Custom ETW

BDESVC Provides BitLocker client services for user interface and auto-unlocking of data volumes

Custom ETW

BTHSERV The Bluetooth service supports discovery and association of remote Bluetooth devices.

Device

SensorsMTPMonitor Monitors MTP (Media Transfer Protocol) sensors (such as a cell phone with a GPS receiver) to communicate sensor data to programs

Device

TabletInputService Enables Tablet PC pen and ink functionality Device

WinDefend Protection against spyware and potentially unwanted software

Group Policy

Trigger Start Servicesdemo

Tip: Optimize with Processor Affinity

Adaptive Display BrightnessAmbient light sensors detect changes in ambient light and adjust the display brightness.If service is disabled, display brightness will not adapt to lighting conditions.If monitor does not contain a light sensor, service can be default state of Manual or Disabled.Service Name (registry): SensrSvc

Device Power Management

Adaptive display brightnessDim the mobile PC display after a period of user inactivityIntelligent policy—timeout automatically adjusts with user inputDoes not interfere with presentations, full-screen media playback

Processor power managementUpdates to core performance state algorithmCore parking

Device Power Management

AudioSupport for the latest Intel HD Audio low-power specificationsUSB audio class selective suspend

BluetoothRadio enters selective suspend when connections are in sniff mode

Wired LAN runtime idle detectionNIC automatically enters D3 when media is disconnected

Power Policy EnhancementsIterative evolution of Vista power policy

Continue 3 plans: Performance, Balanced, Power SaverImproved User Interface elementsNew power settings for Windows 7 featuresSmall changes to idle timeout defaults

OEMs must continue to tailor policy for specific platforms

E.g., meet regulatory compliance standards

New Windows 7 Power PoliciesName GUID Description

Default (Balanced)

AC DC

Unattended sleep timeout

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Determines the amount of inactivity time before the system automatically sleeps if the computer resumed without a user present

2 minutes 2 minutes

System cooling policy

94d3a615-a899-4ac5-ae2b-e4d8f634367f

Determines if Active or Passive cooling should be favored for thermal zones Active Active

Reserve battery level

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Configures the percentage of battery capacity remaining before displaying the reserve battery warning

n/a 7%

AHCI link power mode

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Configures AHCI link power modes (HIPM, DIPM) and link power states (Partial, Slumber, Active)

HIPM, Partial

HIPM, Slumber

Allow System Required

Policya4b195f5-8225-47d8-8012-9d41369786e2

Enable applications to prevent the system from idling to sleep Enabled Enabled

Dim Display After

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Determines the amount of inactivity time before the system automatically reduces the brightness of the display on a mobile PC

5 minutes 2 minutes

Power WMI ProviderEnables power policy configuration through standard WMI interface

Change power setting valuesActivate a given plan

To get started…Change a power setting: Win32_PowerSettingActivate a plan: Win32_Plan.Activate() method

Wake TimersOpportunity to improve mobile PC experience by reducing spurious wake events

E.g., system wakes up in bag due to application request, remains on, drains battery

Windows 7 mobile PCs will not program wake timer alarm by default

Excludes doze to hibernateWake timers continue to be enabled by default on desktop systemsPower policy control to configure wake timers

Improved Low Battery Experience

7%

16%

5%

Automatic Hibernate

All thresholds are configurable in power policy

Idle DetectionWindows 7 is aggressive about placing the system in sleep when idle

User input and application availability requests only

Availability requests allow applications to request temporary overrides on power management

Media center recording service prevents idle to sleep when recording TVWindows Media Player prevents display from turning off while watching DVDPresentation Mode

Idle DetectionWindows 7 improves failed idle detection diagnostics

Use PowerCfg utility to inspect for requestsPowerCfg /REQUESTS

Network file sharingOpen files in a client-side cache (offline files) will not prevent the client from sleeping

Policy override capabilityOption to override individual availability requestsOption to override all availability requests

Idle detection will be based solely on user input

Idle Detection Diagnosticsdemo

Power Efficiency DiagnosticsDesigned to evaluate problems when the system is idle

Close open applications and documents“PowerCfg /ENERGY” at the command line to start tracingIncluded with Windows 7 only

Leverages new inbox ETW instrumentationAdvanced users can run utility and view HTML output

Automatically executed when the system is idleReports data to Microsoft via Customer Experience Improvement Program (CEIP)

Power Efficiency DiagnosticsPowerCfg utility detects energy efficiency problems:

USB device selective suspendProcessor Power Management (PPM) Inefficient power policy settingsPlatform timer resolutionPlatform firmware problems… and others

Helps detect major problems at time of system integrationHTML Output can be viewed by End Users“PowerCfg /ENERGY” at the command line to start tracingWindows 7 only—leverages new inbox ETW* instrumentation

*Event Tracing for Windows (Xperf)

Power Efficiency DiagnosticsPowercfg.exe

demo

Power Efficiency DiagnosticsDetected problems

Problem Area Data Collected Warning Threshold Error

Threshold

USB Device Selective Suspend

Individual device suspend transitions% of time device was in suspend state

< 80% suspend time

< 50% suspend time

Power Policy Settings

Idle timeouts (dim, display, sleep)PPM configurationPower plan personality802.11 Wireless Power Save

Idle timeouts < EnergyStar 4.0 Recommendations

Idle timeouts disabled

Processor Utilization

Overall utilizationPer-process utilization (any process over .1%)Top 3 module utilization in each process

Total utilization >2%

Total utilization > 4%

Power Efficiency DiagnosticsDetected problems

Problem Area Data Collected Warning Threshold

Error Threshold

Timer Resolution Requests

Current system timer interrupt period (e.g., 15.6ms)Applications with outstanding timer requests, request amount

None Timer interrupt period < 15.6ms

Power Requests

Applications with outstanding power requests (Display, Sleep, Away Mode) None Each outstanding

power request

Platform Capabilities

Sleep state availabilityDisplay dimming capabilityFirmware validation problemsPCI Express ASPM status

None If any capability is disabled or missing

Battery Capacity

Battery static data (make, model, serial number, manufacture date)Last full charge capacity/design capacity

(Last Full Charge Capacity/Designed Capacity) < 50%

(Last Full Charge Capacity/Designed Capacity) < 40%

Windows 7 Group Policies

Group Policy Power Settingsdemo

Windows 7 Vs Windows Vista

“In a demonstration of two identically configured ThinkPads T400s, Intel and Microsoft claimed that a Windows XP SP2 machine consumed on average 20.2 watts, while the Windows 7 machine consumed 15.4 watts. That translated to about 1.4 hours of additional battery life”. PC Magazine September 2009

question & answer

Review:The Need for Green!Processor Developments inc Core Parking TechnologyWindows Power Management Architecture Using Trigger Start Services, Idle Resource Utilisation, Timer CoalescingEnhanced Power Managements Features: Adaptive display Brightness, Low Power Audio, Bluetooth & Network power Enhancements.Enhancing Notebook & Net book Battery LifePlayback Pipeline scalingUsing Group Policies to configure Power & Performance settings.Power Efficiency Diagnostics: Using PowerCFG.exe Drilldown.Conclusions & Q&A

Thanks for Attending!

Andy Malone MVP, MCTCEO / ConsultantQuality Training (Scotland) Ltd & Dive Deeper Technology Events EMEAAndrew.malone@quality-training.co.uk

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www.microsoft.com/learning

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© 2009 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS,

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