Using the System Setup Program 2-9
Power Management
For certain types of monitors and most EIDE hard-disk
drives, you can reduce system power consumption by
enabling the power management feature. With Power
Management enabled, these monitors and drives
automatically switch into low-power mode during
periods of system inactivity.
Power Management can be implemented at three levels—
Maximum, Regular, and Minimum. (The different levels
apply to the monitor only; hard-disk drive operation is
the same for all three.) The default setting for this
category is Disabled.
Saving Monitor Power
If you have a Video Electronics Standards Association
(VESA®) Display Power Management Signaling
(DPMS)-compliant monitor, enabling the Power
Management category reduces monitor power consumption
during periods of keyboard and mouse inactivity.
NOTE: The power management feature monitors activity of
a mouse connected to the Personal System/2 (PS/2)-
compatible mouse port.
By setting Power Management to Maximum, Regular, or
Minimum, you can set predefined time-out periods (see
Table 2-2) for the two successive monitor shutdown
stages, standby and off.
NOTE: Each monitor manufacturer defines the details of
the shutdown stages for its own monitors. But in all cases,
power consumption decreases with each stage from “on”
(full power) to “standby” (reduced power; the display
image usually disappears) to “off” (where power con-
sumption is minimal). To define these stages for your
monitor, see the documentation that came with the monitor .
From either shutdown stage, you can return full power to
the monitor in one of the following ways:
•For most DPMS-compliant monitors, any
subsequent activity—including moving the mouse—
should return full power to the monitor.
•A few DPMS-compliant monitors require that you
turn monitor power off and then on again to return to
full power.
Check your monitor documentation for information on
how your monitor is designed to operate.
Saving EIDE Hard-Disk Drive Power
For most systems, enabling Power Management at any
level causes EIDE hard-disk drives to switch to low-
power mode after about 20 minutes of system inactivity
(see Table 2-2).
NOTES: All EIDE drives shipped with your system
support this feature. (For more information on Energy
Star systems, see “Energy Star Compliance” in
Chapter1.)
However, not all EIDE hard-disk drives support this
feature. Enabling this feature for drives that do not
support it may cause the EIDE drive to become
inoperable until the computer is restarted and the Power
Management category is disabled.
In low-power mode, the disks inside the drive stop
spinning. They remain idle until the next drive access,
which causes them to start spinning again. (Because the
disks take a few seconds to regain full speed, you may
notice a slight delay when you next access the hard-disk
drive.)
When Power Management is set to
Disabled (the
default), the disks spin constantly as long as the
system is turned on.
CAUTION: Check your monitor documentation to
make sure you have a DPMS-compliant monitor
before you enable this feature. Otherwise, you risk
damaging the monitor.

Table 2-2. Power Time-Out Periods

Power
Manage-
ment
Setting
EIDE Drive
Spindown
Time-Outs
Monitor
Standby
Time-Outs
Monitor
Off
Time-Outs
Disabled Never Never Never
Maximum 20 minutes 10 minutes 1 hour
Regular 20 minutes 20 minutes 1 hour
Minimum 20 minutes 1 hour Never