>> It's a power saving state the CPU can be put in when idle. There are >> C0-C3 where C0 is the full "working state". For more info: >> http://acpi.sourceforge.net/documentation/processor.html > > > An ACPI method of doing cpufreqd? > No it has nothing to do with clock frequency. If I understand It correctly, it shuts off certain functions of the CPU.