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Power Management Settings: Dell Latitude CPt S-Series User's Guide
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Power Management Settings: Dell™ Latitude™ CPt S-Series User's Guide
In general, the lower the value you set for each power conservation feature, the longer
the battery's charge lasts. On the other hand, setting high values tends to optimize the
computer's performance.
To evaluate the way that different settings affect how long you can operate the
computer on battery power versus the relative efficiency of how the software performs,
experiment as follows:
- Use the computer with all the options set at their default values.
- Use the computer with all the options disabled or set to Off.
- Use the computer with all the options set to their minimum or maximum values.
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NOTE: For Advanced Configuration and
Power Interface (ACPI)-compliant systems, power management settings, such as key
combinations and standby or hibernate mode, are controlled exclusively by the Power
Management or Power Options Properties window in the Control
Panel. See Power Management
Properties for Windows 98 and Power Options Properties for
Windows 2000. In other systems, power management settings are
controlled from the System Setup program. |
Table 1 identifies the power management key combinations for the
Microsoft® Windows 95 and Windows NT operating systems, which are Advanced Power
Management (APM)-compliant. These key combinations also work with APM-compliant Windows
98.
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NOTE: To use key combinations on an
external keyboard, enable the External Hot Key option in the System Setup program,
and press <Scroll Lock> instead of <Fn>. |
Table 1. Key Combinations to Activate/Deactivate Features
| Feature |
Activate/Deactivate |
| Turn off display |
To
activate, press <Fn><d>. To
deactivate, move the cursor or press a key on the integrated or external keyboard. (If
nothing happens, the computer may be in suspend mode. Press the power button to resume
normal operation.) |
| Turn off hard-disk drive |
To
activate, press <Fn><h>. Automatically
deactivates when the hard-disk drive is accessed.
NOTE: If a modular hard drive is installed in the C/Dock media
bay, you cannot turn off the hard-disk drive by pressing <Fn><h>. |
| Suspend mode Standby mode (Windows 98 systems) |
To
activate, press <Fn><Esc>. To deactivate, press the power
button. |
| Suspend-to-disk mode |
To
activate, press <Fn><a>. (On a French keyboard, press <Fn><q>.)
To deactivate, press
the power button. |
Table 2 identifies the power management key
combinations for the Microsoft Windows 2000 and Windows Me operating systems, which are
ACPI-compliant. They also work with ACPI-compliant Windows 98.
|
NOTE: To use key combinations on an
external keyboard, enable the External Hot Key option in the System Setup program,
and press <Scroll Lock> instead of <Fn>. These key combinations function for
ACPI-compliant systems. |
Table 2. Key Combinations to
Activate/Deactivate Features
| Feature |
Activate/Deactivate |
| Sleep mode (ACPI-compliant Windows 98
systems) Standby mode (Windows 2000 systems) |
To
activate, press <Fn><Esc> or the Sleep key on some external keyboards.
To deactivate, press the power button. |
One way to conserve power on the computer is to close the display
when the computer is not in use.
Closing the Display on Windows 95, Windows 98 and Windows NT
Systems
When you close the display and an external monitor is not
connected, the computer's display shuts off automatically. If you set the Display
Close option, in System Setup, to Suspend, the computer enters
the suspend mode when the display is closed. If you set the Display Option to
Active, the display shuts off when it is closed and does not enter the
suspend mode.
|
NOTE: If an external monitor is connected when you
close the display, the computer does not activate suspend mode. You can still use the
external monitor. |
If the computer detects a wakeup alarm or receives a modem call
while the display is closed, the computer handles the alarm or answers the call. After
such input/output (I/O) activity ceases, the computer waits 1 minute before reactivating
suspend mode.
To resume work, open the display. (The computer may take several
seconds to resume operation.)
Closing the Display on Windows 98, Windows 2000, and Windows Me
Systems
When you close the display and an external monitor is not
connected, the computer's liquid crystal display (LCD) shuts off automatically. You can
set the Display Close option, in the Power Management
or Power Options Properties window in the Control Panel
to several selections, such as Standby, Hibernate, or
Power Off. The computer performs the specified operation when the display
is closed.
|
NOTE: If an external monitor is connected when you
close the display, the computer does not activate standby or hibernate mode. You can still
use the external monitor. |
If the computer detects a wakeup alarm or receives a modem call
while the display is closed, the computer handles the alarm or answers the call. After
such I/O activity ceases, the computer waits 1 minute before reactivating standby or
hibernate mode.
To resume work, open the display. (The computer may take several
seconds to resume operation.)
If your computer is running the Microsoft Windows 95 or Microsoft
Windows NT operating system, suspend mode stops almost all computer activity, but leaves
the computer ready to resume operations immediately in about 20 to 30 seconds. Use suspend
mode whenever you leave the computer unattended.
|
NOTE: Systems
that are ACPI-compliant, such as Windows 2000, Windows Me, and some Windows 98 systems, do
not support suspend mode. ACPI-compliant systems support standby mode and hibernate
mode. See the Microsoft Windows 2000 Help for information on power management settings. |
Suspend mode conserves battery power by turning off the microprocessor clock; the
display; the hard-disk drive; the CD-ROM, CD-RW, DVD-ROM, or LS-120 drive module (if
installed); the external monitor connector; the external keyboard (if attached); the
parallel port; the serial port; the touch pad; and the diskette drive.
You can activate suspend mode immediately by pressing <Fn><Esc> (or
<Scroll Lock><Esc> on an external keyboard if the External Hot Key
option is enabled in the System Setup program).
When your system is in suspend mode, the power indicator is not lit.
Resume from suspend mode by pressing the power button. The computer may take several
seconds to return to normal operation.
|
NOTE: On resumption from suspend mode, if a
password is set, the system displays the password prompt screen. At the password prompt
screen, if you do not enter a password within 2 minutes, the system returns to suspend
mode. |
If your computer is running the Microsoft Windows 98, Windows 2000,
or Windows Me operating system, standby mode turns off the display,
stops the hard-disk drive, and turns off other internal devices so that the computer uses
less battery power. When the computer resumes operation from standby mode, the desktop is
restored exactly as it was before entering standby mode.
| NOTICE: The computer saves data to
random-access memory (RAM), not to your hard-disk drive, before entering standby mode. If
the computer enters standby mode while running on battery power, data loss from RAM can
occur if the battery discharges completely. |
You can activate standby mode by pressing <Fn><Esc>.To resume operation
from standby mode, press the power button.
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NOTE: With systems running under ACPI, settings
for power management features, such as key combinations and standby mode are controlled
from the Power Management or Power Options Properties
window in the Control Panel. Before activating standby mode, make sure
that you have made the appropriate selections from the Power Management or
Power Options Properties window. |
Suspend-to-disk (S2D) mode copies all system data to a reserved area—the S2D
partition—on the hard-disk drive and then turns off all power to the computer. When
you resume normal operation, the same programs will be running and the same files will be
open that were loaded before you activated this mode.
Place the computer in S2D mode if you intend to store the computer for longer than 40
days. S2D mode preserves the configuration information stored in nonvolatile random-access
memory (NVRAM). The reserve battery maintains this information, but it may run out of
energy after 40 days.
|
NOTE: S2D mode helps preserve system data by
saving it to the hard-disk drive if you are about to run out of battery power. |
To activate S2D, press <Fn><a> (or <Scroll Lock><a> on an
external keyboard if the External Hot Key option is enabled in the System Setup
program). On a French keyboard, press <Fn><q> or <Scroll Lock><q>.
Resume from S2D mode by pressing the power button.
For systems with Softex BayManager installed and running Windows 95 or Windows 98, if
you connect or remove devices while the computer is in suspend-to-disk mode, the computer
automatically recognizes the newly connected devices when it resumes normal operation.
Some PC Cards may not operate correctly after resuming from S2D mode. If you encounter
problems with a card, remove and reinsert the card.
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NOTE: Dell creates an appropriately sized S2D
partition before shipping the computer to you. Use the Suspend-to-Disk utility to remove
the file, to increase the size of the file, or to add the S2D file if you removed it. For
more information about altering or creating a S2D file, see the readme.S2D
file, which can be found in the Dell Utilities folder on your hard-disk
drive or on the S2D diskette that came with your computer. |
Through the Power Options Properties in the Control
Panel for ACPI-compliant systems, you can enable the computer's hibernate
mode.
Hibernate mode copies everything in memory to the hard-disk drive
and then turns off all power to the computer. When you resume normal operation, the same
programs will be running and the same files will be open that were loaded before you
activated this mode.
Place the computer in hibernate mode if you intend to store the computer for extended
periods of time. Hibernate mode preserves the configuration information stored in NVRAM.
|
NOTE: Hibernate mode helps preserve system data by
saving it to the hard-disk drive if you are about to run out of battery power. |
To enable hibernate mode:
- Click the Start button. Point to Settings
and then Control Panel.
- Double-click the Power Options icon.
The Power Options Properties window appears.
- Click the Hibernate tab.
- Select Enable Hibernate Support.
- Click Apply.
- Click the Advanced tab.
Select Hibernate for each of the appropriate options listed under the Advanced
tab.
- Click Apply.
When you shut down your computer, you will see a new option in the Start
menu called Hibernate. See your operating system documentation for
more information on hibernate mode.
Resume from hibernate mode by pressing the power button.
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NOTE: With systems running ACPI, you cannot remove
devices or undock your computer while in hibernate mode.
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Some PC Cards may not operate correctly after resuming from hibernate mode. If you
encounter problems with a card, remove and reinsert the card.
Windows 98 provides the Power Management Properties
window for setting power conservation features.
To access the Power Management Properties window and set the
power management features, perform the following steps in Windows 98:
- Click the Start button, point to Settings, and click Control
Panel.
- Double-click the Power Management Properties icon.
The Power Management Properties window contains the following
tabs:
- Power Scheme — allows you to select one of three power
mode settings.
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NOTE: With systems running ACPI, select the Notebook/Portable
setting as the Power Scheme to conserve battery life while the system is
in standby mode. If the Always On setting is selected, the battery life
may be much shorter when in standby mode.
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- Alarms — allows you to set the Low Battery and Critical
Battery alarms to alert you when the computer battery falls below a certain
percentage. When you received your computer, the Low Battery and Critical
Battery alarms check boxes were not checked. Dell recommends that you do not select
these options.
- Power Meter — allows you to view the percentage of
battery life remaining when your computer is operating on battery power. If your computer
is operating on AC power, the computer displays a message.
- Advanced — allows you to display the Power
Meter on the Windows 98 taskbar and to display a password prompt when the computer
resumes from standby mode.
- Hibernate (ACPI only) — allows you to enable the
hibernate feature.
Dell provides Softex software compatible with the Power Management Controller, which
allows you to suspend and resume your portable computer without affecting your ability to
use the docking station or its media bay.
Windows 2000 and Windows Me provide the Power Options Properties
window for setting power conservation features. By allowing you to create your own power
schemes, the power options feature allows you to reduce the power consumption of your
computer devices.
To access the Power Options Properties window and set the
power management features, perform the following steps:
- Click the Start button, point to Settings, and click Control
Panel.
- Double-click the Power Options Properties
icon.
The Power Options Properties window contains the following tabs:
- Power Scheme — allows you to select one of three power
mode settings.
|
NOTE: To conserve battery life while the system is
in standby mode, set Power Scheme to Notebook/Portable
(for Windows 2000) or Portable/Laptop (for Windows Me). If Power
Scheme is set to Always On, the battery life may be much
shorter when in standby mode. |
- Alarms — allows you to set the Low Battery and Critical
Battery alarms to alert you when the computer battery falls below a certain
percentage. When you received your computer, the Low Battery and Critical
Battery alarms check boxes were not checked. Dell recommends that you do not select
these options.
- Power Meter — allows you to view the percentage of
battery life remaining when your computer is operating on battery power.
- Advanced — allows you to specify the
actions (standby, hibernate, or power off) of the power button, the sleep button, and
closing the display.
- Hibernate — allows you to enable the hibernate feature.
See your operating system documentation for more information on Power
Options Properties.
The EPA’s ENERGY STAR®
Computers program is a joint effort between the EPA and computer manufacturers to reduce
air pollution by promoting energy-efficient computer products. The EPA estimates that use
of ENERGY STAR® computer products can save computer
users up to two billion dollars annually in electricity costs.
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