Random idea on cpu power usage / scaling

[aaa]

I'm talking about CPU scaling here. You know, when the cpu scales down to 600mhz or whatever and jumps to full speed when needed.

Here's the situation on Linux (I don't know how Windows does it but I assume it uses polling as well). With the default settings (ondemand), the speed stays at lowest, and when the there's high CPU activity it jumps straight to fullspeed, then checks to see if the speed needs to be pared down by dropping the multiplier a level or two. The way it detects CPU activity is by polling, every X microseconds or whatever it is (this is adjustable btw).

However, if you pay close attention you'll notice a difference in snappiness when you compare "ondemand" vs max speed all the time (and the "conservative" Linux setting is even slower). Also, the polling for CPU activity itself eats energy (by waking up the sleeping CPU). If you increase the poll rate, it feels snappier but reduces CPU sleep time, and vice versa.

My idea is to have the initial "jump to fullspeed" handled by hardware, instead of software polling. It makes sense, instead of waiting a tenth of a second for the software to notice, you are at full speed right away (and thus you get both snappiness and powersavings). Better yet, some way could be devised to totally eliminate the polling and have the software only be notified when need be.

So yeah, that's my random idea dump right there. Thoughts? (like "Does the polling even make more than a teeny power difference anyways?")