Dell LATITUDE D400 - Manual (Page 39)

Battery Optimized Performance — Processor speed is optimized for battery power even if the computer is connected
to an electrical outlet.
To change additional Intel SpeedStep options:
1. Click Advanced and then click one of the following options:
Disable Intel SpeedStep technology control
Remove flag icon (from the notification area)
Disable audio notification when performance changes
2. Click OK to accept any changes, and then click OK to close the Intel SpeedStep® technology window.
You can also change the Intel SpeedStep settings by right-clicking the flag icon in the notification area.