Can P-states save overall energy?

Part of the reason I've been so silent recently is because I've been really really busy. (Aren’t we all?) But it also has to do with a short segment I had written on P-states and energy savings. This brief segment outlined a relationship between processor voltage, leakage current, frequency and power. My conclusion was that P-states not only reduced your peak thermal power but also allowed you to reduce your total energy usage.


So there I was, finger poised above the "post" button, when a nagging thought raised its ugly head. What if I was wrong?  


I set out to find the original references that supplied the basis of my post to be. Unfortunately, all the references seemed to have vanished from the face of the earth. Thinking about it, I could see only two possibilities of how this had happened. Perhaps I didn't remember the articles correctly, recalling a relationship where there was none. "Nah," I said to myself in response. The other possibility was that there existed a far ranging government conspiracy to erase all such references to this relationship. "Uh huh, that's got to be it." Fortunately, I soon got my damaged ego under control. I realized that I had to try harder to validate my facts.


Here I am, a couple of months later, and I have yet to be able to validate the relationship I recall existing between voltage, frequency, leakage current and power.


So here's what I’m going to do. I'm posing this question to you, gentle readers.


QUESTION: Can operating in a higher P-state (i.e. lower voltage and lower frequency) result in any total energy savings? (I'm assuming that the processor doesn't have C-states, meaning it always operates in C0.)


Constructive comments, yea or nay, are welcome.  

Per informazioni complete sulle ottimizzazioni del compilatore, consultare l'Avviso sull'ottimizzazione