You will be able to find information about all Intel Processor on ark.intel.com
On the following PDF, on pag 47 is some information about power management on Ivy Brigde processors.
Thanks a lot.
I have done a lot of search.Actually I think such information may not be maintained by the company. It's not worthy.
The only possibility is that in some research papers, such information might be mentioned as they use different processors for their evaluation. And another reference I found is this :
In it there is an AMD six core Opterons processor that really supports quite some frequency levels. What I need is an CPU with at least 4 cores and better more frequency levels