Dell Dimension XPS 50 Reference Manual page 152

B-18 Dell Dimension XPS Txxx and Txxxr Systems Reference and Troubleshooting Guide
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Power Enables or disables Inactivity Timer and Hard Drive
Management
options.
Inactivity Timer Determines the period of system inactivity (between 1 and
120 minutes) before certain system components enter a
low-power mode. To disable power management, leave this
option set to Off (default).
NOTE: Leave this option set to Off if your operating system
has power management controls.
Hard Drive When set to Enabled (default), Hard Drive allows most
EIDE hard-disk drives to automatically switch into low-power
mode after a specified period of system inactivity (called a
time-out). The time-out period is set with the Inactivity
Timer option. When Hard Drive is set to Disabled, hard-
disk drives do not switch into low-power mode