I hope it is not confidential information. For example, AMD and Nvidia both declare this information.
Public information is available on http://www.intel.com/p/en_US/support/highlights/graphics/cp3-hd4000 or http://intellinuxgraphics.org/.
You should also come to our webinar about Writing Efficient Code for OpenCL Applications on 3rd Generation Intel Core Processors. Where you will learn more.