Windows Vista Power Guide

By Kristan M. Kenney

Since the introduction of the Windows Vista operating system, there have been many rumours and complaints made about the way that the operating system manages power settings and how this can impact the battery life and usage on notebook computers. Generally, Windows Vista manages power as well as its predecessor, Windows XP, although in some configurations it can be a little more demanding on your battery.

This guide will help you get the most out of your notebook battery when running Windows Vista.

First of all, we will want to create a custom power profile. To do this:

  1. Click on the Start button and then click on Control Panel.
  2. In the Control Panel window click on “System and Maintenance”.
  3. In the System and Maintenance window click on “Power Options”.
  4. In the task pane on the left hand side click on “Create a power plan”.

From the options that are listed on the Create a Power Plan screen, we will want to select our “Power saver” as the power plan to base our new plan from. Give your plan a name under the “Plan name” field, for this guide I will be using “Mobile”.

Once Windows has created the power plan it then redirects you to the “Edit Plan Settings” screen, which will allow you to customize settings further.

Under “On battery” you will see three options: “Turn off the display”, “Put the computer to sleep”, and “Adjust display brightness”. I recommend using the following settings for these options:

Turn off the display: 2 minutes

Put the computer to sleep: 10 minutes

Adjust display brightness: 40% (a little less than half way to the left hand side of the slider bar).

After setting these values click on the “Create” button, this will create our plan. Next we will want to further customize some of the power settings that are available to us for a better experience.

In the Power Options screen under “Plans shown on the battery meter” you will see three plans, one of which will be the “Mobile” plan that you just created. Underneath of it you will see “Change plan settings”, click on this button. This will return us to the “Edit Plan Settings” window. Underneath of the options that you set earlier you will see “Change advanced power options”, click on this to display the “Power Options” dialog.

There are several settings listed here, with sub-settings for when you are on battery and when you are running from your notebooks AC adapter. Expand these values by double clicking on them or by clicking on the [+] buttons next to each item. I recommend setting the options to the following values (for descriptions of these values and what they do, please scroll down to the bottom of this configuration list):

Additional settings
Require a password on wakeup
On battery: Yes
Plugged in: Yes

Hard disk
Turn off hard disk after
On battery: 3 minutes
Plugged in: 20 minutes

Wireless adapter settings
Power saving mode
On battery: Maximum power saving
Plugged in: Maximum performance

Sleep after
On battery: 10 minutes
Plugged in: 60 minutes

Allow hybrid sleep
On battery: Off
Plugged in: Off

Hibernate after
On battery: 180 minutes
Plugged in: 1080 minutes

USB settings
USB selective suspend setting
On battery: Enabled
Plugged in: Disabled

Power buttons and lid
Lid close action
On battery: Sleep
Plugged in: Sleep

Power button action
On battery: Sleep
Plugged in: Sleep

Sleep button action
On battery: Sleep
Plugged in: Sleep

Start menu power button
On battery: Sleep
Plugged in: Sleep

PCI Express
Link state power management
On battery: Maximum power savings
Plugged in: Maximum power savings

Processor power management
Minimum processor state
On battery: 5%
Plugged in: 5%

Maximum processor state
On battery: 50%
Plugged in: 100%

Search and Indexing
Power Savings Mode
On battery: Power saver
Plugged in: High Performance

Turn off display after
On battery: 2 minutes
Plugged in: 15 minutes

Adaptive display
On battery: On
Plugged in: On

Display brightness
On battery: 25%
Plugged in: 80%

Multimedia settings
When sharing media
On battery: Allow the computer to sleep
Plugged in: Prevent idling to sleep

Critical battery action
On battery: Hibernate
Plugged in: Do nothing

Low battery level
On battery: 5%
Plugged in: 5%

Critical battery level
On battery: 3%
Plugged in: 3%

Low battery notification
On battery: On
Plugged in: On

Low battery action
On battery: Do nothing
Plugged in: Do nothing

Descriptions of each setting:

Require a password on wakeup: This setting is pretty self explanatory. If you enable it, Windows will prompt you for your password when you resume the computer from sleep or hibernation. If you disable it, Windows will not prompt you and instead will resume directly to the desktop.

Hard disk settings: This setting allows you to control the amount of time that passes before your computer turns your hard disk off or spins the disk down to a low power state.

Wireless adapter settings: If your computer has a wireless network adapter, this option will allow you to control how much power it consumes. On a “low power savings” mode, your wireless adapter will consume more power and you will get greater performance. “Maximum power savings” will allow you to save more power at the cost of network performance.

Sleep: Self explanatory – this allows you to select the amount of time that passes before the notebook puts itself into a low power sleep state.

Allow hybrid sleep: This setting allows you to control the new hybrid sleep function in Windows Vista. This new sleep mode is a combination of both hibernation and sleep, where your machine is powered down to a low power state and the contents of your memory are still in RAM as well as saved to the hard drive. In the event of a power outage while in sleep mode, this will save your behind. But on notebook computers it is recommended to have this set to off. Why? Simple. Notebooks have batteries, and even if the battery drops down to a critical level while in sleep mode, Windows will save the contents of your memory to disk and power off your system. The only reason you would want to have hybrid sleep on in a notebook is if your battery is prone to falling out, or in the case of some Dell notebooks, exploding (although then your machine won’t be powering back on anyway).

Hibernate after: This setting controls the amount of time that passes before the system saves the contents of your memory to disk and powers the system off (therefore saving battery power).

USB selective suspend setting: Powers down unused USB ports after a set period of time. On some notebooks with built-in webcams, this can cause issues with being able to use the camera after resuming from a sleep state. Please check with your notebook manufacturer for updated drivers and information.

Power buttons and lid: Again, this one is pretty self explanitory. The options listed allow you to control what closing the lid on the notebook does, change the default action for the physical power button on the computer itself, and the default action for the Start Menu power button.

PCI Express Link State Power Management: Allows the computer to control how much power is dedicated to the PCI Express bus at any given time. This is especially important if you have a high-end gaming graphics card in your notebook such as a mobile NVIDIA GeForce 8700.

Processor power management settings: Throttles your computer to a certain percentage when running on battery or on AC power. Great for saving power on the road if you aren’t going to be running any intensive applications. NOTE: This setting does not always scale to the percentage you choose, especially on certain Intel based processors that can only step down their clock speed by multiplier. In this case, your most likely going to see your processor throttled at 50% even if you select a lower percentage.

Search and Indexing settings: Controls how much CPU time the Windows Search service is allowed to consume. To keep the index up to date, Windows must crawl through files in order to inspect their contents and uses a percentage of your processor cycles. If you are running on battery power, it is recommended to use “Balanced” or “Power saver” to save a few extra minutes on your battery life. For AC power, I recommend using “High Performance” as this allows the indexer to update the search index in almost real-time.

Display settings: Allows you to control the timeout period before the display powers down, and allows you to control the brightness of the display. If you are working in an area where you can see your display fine on a low backlight level it is highly recommended as this will save you some time on your battery.

Multimedia settings: If your notebook is set up as a Windows Media Center or sharing files over the network through the Windows Media Network Sharing Service, you can prevent the computer from idling to sleep (for instance, you are not actively at the computer and you are streaming media to another computer in the home). By doing so, you can make sure that your media experience will not be interrupted. It is recommended that when you are using battery power to allow the computer to sleep, because otherwise your battery could drain to 0% and if Windows does not get a chance to hibernate you may lose any un-saved work.

Battery settings: Self explanitory. These settings allow you to control when you would like to be notified that your battery is at a low or critical level, and allows you to control what Windows will do in a low battery situation (such as sleep or hibernate).

If you find that your display is too dim, adjust the “Display brightness” settings to your personal preference.

Some things you may wish to do to conserve battery power further:

  • Exit the Windows Sidebar: Some third party gadgets will use CPU time to update real-time information. To conserve battery power, exit the Windows Sidebar by right-clicking on the Windows Sidebar icon in the notification area next to the clock, and click on Exit Sidebar.
  • Remove any CD or DVD discs from your optical drive: If you open the Computer window or any other Windows Explorer window, there is a chance that Windows will try to poll the drive, causing the disc to spin up, which can drain battery power. It is always a good idea to remove discs from optical drives when not in use.
  • Close any unused applications running in the background: Applications running in the background can use memory, cause paging to the disk (which can cause loss of battery life), and use CPU cycles. It is always a good idea to close any unused programs (running either in the taskbar or in the notification area next to the clock) when you are running on battery power to conserve as much as possible.
  • Use Windows Mobility Center to change settings on-the-fly: If you wish to change display brightness settings, toggle wireless on/off, or change any other mobile settings quickly, you can use the Windows Mobility Center, which is a new feature found in Windows Vista geared toward mobile computer users. There are two ways to bring up the Windows Mobility Center. Right click on the Power icon in the notification area and click on “Windows Mobility Center”, or hold down the Windows flag key and tap X (Win + X) on your keyboard.

These settings and following the above advise should provide an optimal mobile experience with Windows Vista.

When using these settings:

  • Performance is not lowered when plugged in.
  • Performance is lowered in order to save battery life when running on battery power.
  • Windows Aero transparency is disabled when running on battery power, and is re-enabled when the notebook is plugged in.
  • Search indexing performance is lowered slightly in order to conserve power, but runs at a high performance or “normal” state when plugged in.
  • The screen is dimmed considerably to conserve battery power. If required, you can modify your brightness to your liking by using the Windows Power Options or by using the function keys found on most notebooks.
  • For extra battery life, consider turning off any wireless network adapters when you do not need internet connectivity.

I have fully tested these settings on my HP Pavilion dv6335ca notebook computer with the following specifications:

  • Intel Centrino Duo technology featuring an Intel Core 2 Duo T5300 1.73GHz processor
  • 2.00 GB of DDR2 SDRAM memory
  • 15.4″ (1280×800) widescreen display
  • 160 GB Serial ATA 7200 RPM hard drive
  • Regular 6-cell lithium-ion notebook battery