User's Manual Part 2

Setup Configuration Utility (SCU)5-16
SpeedStep Support
Enables or disables the Geyserville feature of the CPU. The Geyserville
feature helps conserve battery life by decreasing the CPU’s running speed
under certain conditions while still maintaining a high performance. If this
item is enabled, the CPU will automatically change its speed whenever
necessary based on the “Power Scheme” setting in Windows’s Control Panel.
If this item is disabled, the CPU will always run in the lowest speed (600
MHz).