I think that clock rate of processor determines the speed of core, in my case it is 1.86GHz. But If I am not wrong, it also determines that how much energy it will consume. If you have more frequency then more power it will consume.

I choose Power Saver scheme to increase my battery life, however it reduces my core speed to half of the actual speed. I understand this happens because of SpeedStep, but I don't see any slowdown of my computer.

So my problem is why we have such high frequency cores as it uses too much power. We can use low frequency cores.

Actually I get confused between the two terms Speed of the processor and its frequency.

So how much important is the frequency of core in case of any processor.