Windows
 

Configuring Windows 8 Computers : Configuring Power Management Settings (part 1)

12/15/2012 5:45:37 PM

Power management settings control the behavior of a computer in different power use situations, such as when it is plugged in or running on a battery. Although all computers should be configured with power management settings to save energy, power management settings on laptops help to balance performance against energy usage. In some cases, you’ll want to reduce laptop responsiveness and overall performance to increase the battery life, enabling the laptop user to run the laptop on battery for longer periods of time. In other cases, you might want to ensure moderate performance and a moderate battery life, or you might want to ensure maximum performance regardless of how this affects battery life.

The core aspects of power management are managed using power plans, which are collections of power management settings that control power usage and consumption. A computer can have multiple power plans, but only one can be active at any given time. In addition to power plans, most computers have preset behaviors for when the power button is pressed and for when the sleep button is pressed, and laptops have a default action for when you close the laptop’s lid. Typically, closing a laptop’s lid puts it into sleep mode, pressing and holding the power button shuts down a computer, and pressing the sleep button puts a computer into sleep mode. Through systemwide settings for power options, you can customize the power button and password-protection-on-wakeup behavior to meet the needs of individual users or groups of users.

1. Managing Power Options from the Command Line

Windows 8 includes the Power Configuration (Powercfg.exe) utility for managing power options from the command line. You can view a list of parameters for this utility by typing powercfg /? at a command prompt. The parameters you’ll work with most often include:

  • –a Lists the available sleep states on the computer and the reasons why a particular sleep state is not supported.

  • –d [guid] Deletes the power plan specified by the globally unique identifier (GUID).

  • –devicequery all_devices_verbose Lists detailed power support information for all devices on the computer. Be sure to redirect the output to a file because this list is very long and detailed.

  • –energy Checks the system for common configuration, device, and battery problems and then generates an HTML report in the current working directory.

  • –h Toggles the hibernate feature on or off.

  • –l Lists the power plans configured on a computer by name and GUID.

  • –q [guid] Lists the contents of the power plan specified by the GUID. If you don’t provide a GUID, the contents of the active power plan are listed.

  • –requests Displays all power requests made by device drivers. If there are pending requests for the display, these requests would prevent the computer from automatically powering off the displays. If there are pending requests for any device including the display, these requests would prevent the computer from automatically entering a low-power sleep state.

  • –s [guid] Makes the power plan specified by the GUID the active power plan.

  • –x [setting] [value] Sets the specified value for the specified setting in the active power plan.

Note

By default, Windows 8 computers use hybrid sleep instead of hibernate. Hibernate should not be configured without first determining compatibility. Note also that the Power Configuration utility (Powercfg) accepts either a hyphen (-) or a slash (/) for commands. I prefer to use a hyphen because of its location on the keyboard.

The following is a sample listing returned by typing powercfg –l at a command prompt:

Existing Power Schemes (* Active)
-----------------------------------
Power Scheme GUID: 381b4222-f694-41f0-9685-ff5bb260df2e (Balanced)
Power Scheme GUID: 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c (High performance)
Power Scheme GUID: a1841308-3541-4fab-bc81-f71556f20b4a (Power saver)
Power Scheme GUID: c1d97820-3148-42a9-a587-75d618a9bb2b (Graphics Dept) *

The active plan is marked with an asterisk. From this listing, you can determine that this computer has four power plans and the active power plan is the Graphics Dept plan.

If you want to configure power plans or modify power settings using Powercfg, you need to do so by using an elevated command prompt. When a parameter requires a GUID, the easiest way to obtain this value is to type powercfg –l at an elevated command prompt, and then copy the value for the appropriate power plan. For example, if you want to make the Balanced plan the default plan for the computer in the previous example, you would type the following at an elevated command prompt:

powercfg -s 381b4222-f694-41f0-9685-ff5bb260df2e

You determine the power modes that a computer supports by typing powercfg –a at a command prompt. Powercfg will list exactly what modes are and aren’t supported, such as the following:

The following sleep states are available on this system:
Standby (S1 S3)
Hibernate
Hybrid Sleep
The following sleep states are not available on this system:
Standby (S2)
The system firmware does not support this standby state.

If a computer has problems entering sleep or hibernate mode, you can use powercfg –a to possibly determine what is causing the problem. If the firmware doesn’t support a particular mode, you may in some (limited) cases be able to update the firmware to gain support for a particular mode. If a device that doesn’t support a particular mode is causing a problem, you may be able to remove the device and replace it with a compliant device.

Any time you want to evaluate a computer’s power configuration and device compatibility, you can generate a Power Efficiency Diagnostics report by entering powercfg –energy at a command prompt. When you run powercfg –energy, the report is generated as an HTML document called Energy-Report.html. In the report, you’ll see the results of power management compliance for devices. Any device that doesn’t support power management appropriately will be listed, along with the error details. For example, if a USB device doesn’t properly enter the Suspend state, you’ll see the detailed information about the errors encountered and the device configuration. If a power management capability has been disabled due to a compatibility issue, you’ll see this. For example, if the PCI Express Active-State Power Management feature isn’t supported on the hardware and the feature has been disabled because of this, you’ll see this listed in the report. Warnings and additional information about devices and compatibility are provided as well, including details on supported sleep states and processor power management capabilities.

Note

REAL WORLD For laptops, important information is provided on battery charging and battery life. If a battery is nearing or at the end of its useful life, you’ll be able to tell this because the battery life is limited and the battery details will show the battery isn’t holding a charge like it should. You’ll then know you need to replace the laptop’s battery.

To dig even deeper into power management issues, you can get comprehensive power support details for every device on the computer by entering the following command:

powercfg -devicequery all_devices_verbose > power.txt

where Power.txt is the name of the file in the current working directory in which the power information will be saved.

When you’ve configured Windows PowerShell for remoting, you can easily execute Powercfg on multiple remote computers. To do this, enter the name of each remote computer to check on a separate line in a file called Computers.txt, and then save this file. Then open an elevated administrator Windows PowerShell prompt and enter the following commands:

$comp = get-content c:\computers.txt
$s = new-pssession -computername $comp
invoke-command -session $s { powercfg.exe -energy }

Here, C:\Computers.txt is the path to the Computers.txt file. Update this path as appropriate for where you saved the file. On each computer, an Energy-Report.html file will be created in the default directory for the user account used to access the computer. If you would rather not have to retrieve the HTML document from each computer, you can write the report to a share and base the report name on the computer name, as shown in the following example:

$comp = get-content c:\computers.txt
$s = new-pssession -computername $comp
invoke-command -session $s { powercfg.exe -energy -output
"\\fileserver46\data\$env:computername.html"}

Here, you write the report to the \\fileserver46\data share and name the file using the value of the ComputerName environment variable. Note that when you work with Windows PowerShell and are referencing commands with executables, you must specify the .exe file extension with the program name.

2. Working with Power Plans

On mobile computing devices, the notification area of the taskbar includes a Power icon. Tapping or clicking this icon shows the battery state and the power plan that you are using. Tapping or clicking either of the links provided in the notification status dialog box opens the Power Options page in Control Panel. Out of the box, most configurations of Windows 8 have three preferred power plans:

  • Balanced A power usage plan that balances energy consumption and system performance. The processor speeds up when more resources are used and slows down when less are needed. This is the default power plan. Use this plan for users who work with a wide variety of applications, including those that are moderately graphics-intensive, such as Microsoft PowerPoint, and those that are not graphics-intensive, such as Microsoft Word and Microsoft Outlook.

  • High Performance A high-power usage plan that optimizes the computer for performance at a direct cost to battery life. This plan ensures that you always have enough power for using graphics-intensive programs or playing multimedia games. Use this plan when performance is essential and users work primarily with graphics-intensive applications or applications that perform complex arithmetic calculations. Note that you may have to tap or click Show Additional Plans to view this power plan.

  • Power Saver A low-power usage plan designed to reduce power consumption. This plan slows down the processor to maximize the battery life. Use this plan for users who work primarily with non-graphics-intensive applications, such as Word and Outlook.

Power plan settings are divided into two general categories: basic and advanced. Basic power settings control when a computer dims or turns off its display, as well as when the computer enters sleep mode. It’s important to note that mobile computing devices have On Battery and Plugged In settings that can be configured independent of each other. For example, you may want a computer’s display to dim after 2 minutes of inactivity when on battery or after 5 minutes of inactivity when plugged in.

Advanced power settings determine precisely whether and when power management components on a computer are shut down and how those components are configured for performance. The advanced power settings available depend on the computer’s configuration and include:

  • Battery\Reserve Battery Level Determines the percentage of battery remaining that initiates reserve power mode. Typically, the default value is 7 percent, meaning the computer will enter reserve power mode when there is 7 percent of battery power remaining. Although you can set any percentage, a reserve level of 5 to 18 percent is often best.

  • Desktop Background Settings\Slide Show Determines whether the slide show feature for the desktop background is available or paused. The default setting is Available. If you set this option to Paused, background slide shows on the desktop will be disabled.

  • Display\Turn Off Display After Determines whether and when a computer’s display is turned off to conserve power. Use a setting of Never to disable this feature. Use a specific value in minutes to determine how long the computer must be inactive before the display is turned off.

  • Hard Disk\Turn Off Hard Disk After Determines whether and when a computer’s hard disk is turned off to conserve power. Use a setting of Never to disable turning off the hard disk. Use a specific value in minutes to determine how long the computer must be inactive before the hard disk is turned off. Windows 8 provides a combo box for setting numeric values. Tapping or clicking and holding the up or down arrow enables you to rapidly scroll through values. If you scroll down from 1, the next value is Never. You can also type a value. If you enter a value of 0, this is interpreted as Never.

  • Multimedia Settings\When Playing Video Determines the power optimization mode used when playing video. If you set this option to Optimize Video Quality, the computer will use the best playback quality possible for video. If you set this option to Balanced, the computer will use a balanced approach, adjusting playback quality to some degree to save power. If you set this option to Optimize Power Savings, the computer will actively adjust the playback quality to save power.

  • Multimedia Settings\When Sharing Media Determines what the computer does when a device or another computer plays media from the computer. If you set this option to Allow The Computer To Enter Away Mode, the computer will not enter sleep mode when sharing media with other devices or computers. If you set this option to Allow The Computer To Sleep, the computer can enter sleep mode after an appropriate period of inactivity regardless of whether media is being shared with other computers or devices. If you set this option to Prevent Idling To Sleep, the computer will enter sleep mode when sharing media with other devices or computers only if a user puts the computer in sleep mode.

  • PCI Express\Link State Power Management Determines the power saving mode to use with PCI Express devices connected to the computer. You can set this option to Off, Moderate Power Savings, or Maximum Power Savings.

  • Power Buttons And Lid\Power Button Action Specifies the action to take when someone pushes and holds the computer’s power button. You can set this option to Do Nothing, Sleep, Hibernate, or Shut Down.

  • Power Buttons And Lid\Sleep Button Action Sets the default action for the sleep button. Use this setting to override the computer’s default action. You can set this option to Do Nothing, Sleep, or Hibernate. You cannot, however, use an option that is not supported by the computer.

  • Processor Power Management\Maximum Processor State Sets a maximum or peak performance state for the computer’s processor. To save power and reduce energy consumption, lower the permitted maximum performance state. But you lower the performance state at a direct cost to responsiveness and computational speed. Although reducing the maximum processing power to 50 percent or less can cause a significant reduction in performance and responsiveness, it can also provide a significant power savings.

  • Processor Power Management\Minimum Processor State Sets a minimum performance state for the computer’s processor. To save power and reduce energy consumption, lower the permitted minimum performance state—but you lower the performance state at a direct cost to responsiveness and computational speed. For example, a value of 5 percent would lengthen the time required to respond to requests and process data while offering substantial power savings. A value of 50 percent helps to balance responsiveness and processing performance while offering a moderate power savings. A value of 100 percent would maximize responsiveness and processing performance while offering no power savings.

  • Processor Power Management\System Cooling Policy Determines whether the operating system increases the fan speed before slowing the processor. If you set this option to Passive, this feature is limited, and the processor may run hotter than normal. If you set this option to Active, this feature is enabled to help cool the processor.

  • PlanName\Require A Password On Wakeup Determines whether a password is required when a computer wakes from sleep. You can set this option to Yes or No. With domain computers, this option is set to Yes and can be controlled only through Group Policy.

  • Sleep\Allow Hybrid Sleep Specifies whether the computer uses Windows 8 sleep mode rather than the sleep mode used in earlier versions of Windows. You can set this value to On or Off. Hybrid sleep mode puts the computer in a low-power consumption state until the user resumes using the computer. When running on battery, laptops and tablets continue to use battery power in the sleep state, but at a very low rate. If the battery runs low on power while the computer is in the sleep state, the current working environment is saved to the hard disk, and then the computer is shut down completely. This final state is similar to the hibernate state used with Windows XP.

  • Sleep\Allow Wake Timers Determines whether timed events should be allowed to wake the computer from a sleep state. If you set this option to Disable, timed events won’t wake the computer. If you set this option to Enable, timed events can wake the computer.

  • Sleep\Hibernate After Determines whether and when a computer hibernates to conserve power. When a computer goes into hibernation, a snapshot of the user workspace and the current operating environment is taken by writing the current memory to disk. When a user turns the computer back on, reading the memory from disk restores the user workspace and operating environment. In Windows 8, this setting isn’t normally used because the standard configuration is to sleep after a period of inactivity. Use a setting of Never to disable this feature. Use a specific value in minutes to determine how long the computer must be inactive before the computer hibernates.

  • Sleep\Sleep After Determines whether and when a computer enters a sleep state to conserve power. Use a setting of Never to disable this feature. Use a specific value in minutes to determine how long the computer must be inactive before the computer enters a sleep state.

  • USB Settings\USB Selective Suspend Setting Determines whether the USB selective suspend feature is available. If you set this option to Disabled, selective suspend will not be used with USB devices. If you set this option to Enabled, selective suspend can be used with USB devices.

  • Wireless Adapter Settings\Power Saving Mode Specifies the power saving mode to use with any wireless adapters connected to the computer. You can set this option to Maximum Performance, Low Power Saving, Medium Power Saving, or Maximum Power Saving.

As you can see, the advanced power settings control every facet of power management. The differences in the advanced settings are what really set the power plans apart from each other. For example, while the High Performance plan ensures performance by allowing the computer’s processor to always run at 100 percent power consumption, the Power Saver and the Balanced plans reduce energy consumption by configuring the processor to use a minimum power consumption rate of 5 percent and a maximum rate of 100 percent.

When configuring power plans, it is important to allow components to turn off after periods of inactivity. Turning off components separately enables a computer to progressively go into sleep mode. When a computer is fully in sleep mode, all power-manageable components are switched off so that the computer uses less power. When the computer is brought out of sleep mode, the components, such as the monitor and hard disks, are turned back on, restoring the user workspace. You should configure sleep mode so that when a laptop is running on batteries, it goes into power conservation mode when the user is away from the laptop for a relatively short period of time, such as 20 or 30 minutes.

Because a computer can have multiple power plans, each plan can be optimized for the way a laptop is used at a particular time. You can configure multiple power plans for different situations. At home or in the office, laptops might need different power management configurations than they do when users are giving presentations. In one case, you might want to configure the laptop to quickly conserve energy when running on batteries. In another case, you might want to ensure that the laptop never turns off its hard disk or wireless adapters.

 
Others
 
- Windows Small Business Server 2011 : Distributed File System (part 3) - Changing Advanced Settings, Using DFS Replication
- Windows Small Business Server 2011 : Distributed File System (part 2) - Creating or Opening a Namespace Root, Adding DFS Folders
- Windows Small Business Server 2011 : Distributed File System (part 1) - File Replication Service, Installing DFS Management
- Windows 7: Writing Your Text
- Windows 7 : Running Multiple Copies of One Program, Copying Your Screen Content
- Configuring Windows 8 Computers : Managing System Properties (part 3)
- Configuring Windows 8 Computers : Managing System Properties (part 2)
- Configuring Windows 8 Computers : Managing System Properties (part 1)
- Windows Server 2008 : Planning a Terminal Services Deployment (part 2)
- Windows Server 2008 : Planning a Terminal Services Deployment (part 1) - Terminal Services Licensing
- Configuring Windows 8 Computers : Using System Support Tools (part 2) - Managing System Configuration, Startup, and Boot
- Configuring Windows 8 Computers : Using System Support Tools (part 1) - Working with Disk Cleanup, Verifying System Files with File Signature Verification
- Windows Server 2008 Server Core : Working with Data - Working with File Associations and Types, Working with ODBC Data Sources
- Windows Server 2008 Server Core : Working with Data - Performing Bulk File Transfers with the XCopy Utility
- Windows Server 2008 Server Core : Working with Data - Validating File Operations with the Verify Command, Performing Backups with the WBAdmin Utility
- Windows Small Business Server 2011 : Partitions and Volumes (part 4) - RAID-5 Volumes, Mounting a Virtual Hard Disk, Mounting a Volume
- Windows Small Business Server 2011 : Partitions and Volumes (part 3) - Adding a Mirror, Drive Failure in a Mirrored Volume
- Windows Small Business Server 2011 : Partitions and Volumes (part 2) - Extending or Shrinking a Volume
- Windows Small Business Server 2011 : Partitions and Volumes (part 1) - Adding a Partition or Volume
- Windows Small Business Server 2011 : Disk Management - Managing Disks
 
 
Most View
 
- Windows Phone 8 : Working with People - The People Hub (part 5) - Searching for a Contact,Using Jump Lists to Find a Contact
- Windows 7 : Windows Media Player - Learning the Basics (part 3) - Playing Audio and Video in WMP 12
- Exchange Server 2013 : Building an Available Messaging System (part 3) - INTERSITE REPLICATION BANDWIDTH
- Microsoft Access 2010 : Introduction to Relational Database Design (part 1) - Rules of Relational Database Design
- Microsoft Lync Server 2013 Front End Server : Active Directory Preparation
- Windows 8 : Managing disks and storage (part 3) - Using Microsoft Drive Optimizer to organize data
- Windows Small Business Server 2011 : Group Policy Preferences (part 2) - Using Group Policy Preferences for Windows - Drive Maps
- Exchange Server 2013 : The Exchange Management Shell - How Exchange uses Windows PowerShell
- Microsoft Visio 2010 : Distributing Templates and Stencils (part 1) - Creating a Template with a Document Stencil
- Microsoft Project 2010 : Viewing Baselines (part 1) - Tracking Gantt View and the Variance Table
 
 
Top 10
 
- Microsoft Sharepoint 2013 : Administering Sharepoint with Windows Powershell - Basic PowerShell Usage (part 3) - Controlling Output
- Microsoft Sharepoint 2013 : Administering Sharepoint with Windows Powershell - Basic PowerShell Usage (part 2) - PowerShell Help , PowerShell Variables
- Microsoft Sharepoint 2013 : Administering Sharepoint with Windows Powershell - Basic PowerShell Usage (part 1) - Listing the SharePoint Commands
- Microsoft Sharepoint 2013 : Administering Sharepoint with Windows Powershell - Commands
- Microsoft Sharepoint 2013 : Microsoft SharePoint 2013 Management Shell and Other Hosts
- Microsoft Word 2010 : Using Advanced Text Features - Addressing Envelopes
- Microsoft Word 2010 : Using WordArt (part 2) - Changing the Format of a WordArt Object
- Microsoft Word 2010 : Using WordArt (part 1) - Inserting WordArt Text
- Microsoft Word 2010 : Creating and Formatting Text Boxes (part 3) - Formatting Text in a Text Box, Linking Text Boxes
- Microsoft Word 2010 : Creating and Formatting Text Boxes (part 2) - Resizing a Text Box , Moving a Text Box