Haswell CPU's - Explain Turbo Mode?

[stoofa]

Hi,
I'll admit I don't know a great deal about the new Haswell CPU's. We will be getting some workstations with these CPU's within the next month so would like to know more about specific feature - turbo mode.
The CPU we will probably be getting in the workstations is the i7-4770 3.4GHz.
Now I know these are "good clockers" and I'm told that overclocking to 4GHz wouldn't be much hassle. However these are for work use and I don't like running things in an overclocked state.

I see these CPU's have a "Turbo Mode" of 3.9GHz. Is this an automated feature? So the CPU will run at the higher speed when required or when it can?
Or is this a BIOS feature? Do I set the CPU to use Turbo Mode here? Or do I tell the BIOS that CPU should always be running in Turbo Mode?

Would like to get the best possible performance out of the CPU without physically overclocking it.

Thanks.

 

[NoobCannon]

Yes, think of it as intels automatic overclocking, upps the multi when the cpu is in use.

 

[jack.mitchell]

This is a very good post on Intel P-States which properly explains how Turbo mode works amongst other things. It's directly Linux related, but the hardware is no different so the principles stand. Give it a read, and be enlightened.

https://plus.google.com/114657443111661859546/posts/dLn9T4ehywL

 

[stoofa]

Cheers chaps.