Weird Overclock..!!

[Chirag Borawake]

Heyy guys, please help.
The scenario is:

I was rendering a 3d model yesterday, I have core i7 870 stock speeds 2.93ghz.

The thing is, when I start rendering, the CPU goes upto 3.2ghz, and when the rendering is about to finish, it comes to 2.3ghz.

Today when I started my pc, the default was 1.36ghz.

Is it a weird thing that my CPU overclocks and underclocks by itself, without even asking me?

Even the temperatures are normal when it drops down to 1.36ghz. (49degC for each core).

Is it supposed to happen naturally, or is there something to worry about?

Thanks for your help..!!

 

[alyoshka]

No it's nothing to worry about.
The cores are supposed to function at clocks as required by the system, that save power and prolongs the life of the processor.
It is the Hyper Threading that enable the processor to control itself in that way.
When the cores are not needed they end up idling thus leaving very little power consumed and keeping the clocks down.
It is not going to effect the performance of the chip, since, as soon as you need the cores back on during work intensive sessions all of them come on and go higher than the stock speed to make the job faster.

The Processor itself has about a million transistors dedicated to that job (Controlling the cores). So it's a pretty specialized process for the chip to be able to manage to save power and get it fully functional within a fraction of a second.

 

[Chirag Borawake]

Best answer selected by Chirag Borawake.