I've had mine off for so long, and even when it was on, it never did anything I found.
Thats until I found the above links though, which installs the processor settings properly in Windows to allow for this to occur, and to set the Power to Minimal Power Management to allow the voltages to drop, etc.
And there you go
I can still overclock my system though, and when running 3DSmax and games, it uses the overclocked settings, but I have a cooler/quieter system when I usually want it.