The main reason (for me) are badly programmed programs (especially flash!). I don't think it's a good use of my power bill to allow them to overdrive my CPU. So I'd like to be able to disable TurboBoost or set a low max multiplier when I don't need full power, from Windows, without reboot.
Intel does not supply any control tools, just for monitoring (somewhat limited one). Is there any way to achieve this?