It’s one of those things we tend to take for granted. We don’t know why it works, all we know is that it does work, and that’s good enough for us. And that’s just fine, because in most cases, it really doesn’t matter why it works, just that it does (that’s engineering in a nutshell).
Unless, of course, you’re curious, in which case, we’ve got an answer for you! A common misconception is that increasing the voltage gives the CPU the added ‘power’ it needs to run at higher speeds. While it's true that power varies with voltage, it’s actually the current demands of the processor that increase with speed, not voltage demands (when you overclock a CPU, it requires more current at the same voltage, not more voltage with the same current). It doesn't need more power, it needs more current, so feeding it more voltage in an effort to increase power won't help. So why, then, does increasing the voltage a bit often help the CPU run faster, and with more stability? Read on, and we’ll explain.