Under-volting and CPU efficiency

I have a Corsair H80 from back when I was overclocking. But now that I no longer do (due to exploding PSUs), I want to know if i can maintain the stock clock speeds at lower voltages.

In my science practical examination, I learned that lower temperatures decrease the resistance of circuits ( and therefore make more energy usable) 

Does this mean that my stock I5-2500k with a now overkill cooling system could be under-volted to be more power efficient? (eg: 1.0 or 1.1v instead of 1.2)

Don't really have an answer for you other than to give it a try. Undervolting shouldn't hurt anything. The worst that would happen is it won't reach stock clock frequencies. (At least that's my guess)

Well now we have to start from physics and what I can tell you about physics is that silicon's threshold voltage is 0.7volts so under that your little die does not conduct electricity. And now to Intel. If you stress intel cpu to maximize heat or any other stress test it would lower the core voltage. This is normal becuase intel has stated that lowering the vcore under load will protect it from frying. So these days your bios and other settings are so idiotproof that you can freely try your system that how low you can go on your system. Undervoltage does not corrupt your cpu but the malfunctions (shutdowns, BSODS) would cause your OS to be corrupt but these days it's rare. So hit it down a few notch and come back with results.

You get significantly less heat and in consequence less noise by undervolting, and less power consumption. But it doesn't do much for desktops since the i5 2500k already has power saving features that let it run at very low frequencies and voltages during idle or low system load.

TropiKo is true on that becuse if you leave al power saving settings on and also the C1E support, there is really no significant improvement on power consumption.


Well wouldn't undervolting help with temps during big loads?

I've downvolted my Ti PowerBook. I get 15hr battery life on a 10 year old laptop.

if you undervolt, (unless you have a near perfect quality silicon die), your cpu can become un-stable at higher clock speeds.