i7-3930 is a great hexcore CPU if you are willing to spend +300 for the CPU, +200 or more for the motherboard, +50 for quad-channel RAM sets...pair it with an Asus X79 and you get 3x SLI on PciE 3.0 at 16x/16x/8x. Overclock it to 4.5 Ghz and you wouldnt notice the 100mhz less than a 3960x which is $400-500 more...and 12MB L3 is still enough even compared to 3960x 15MB.. the money you'd save could go to SSD, better GPU, etc.
With the temp issues with Ivy's, most people stick with Sandy for the overclocking unless they need Ivy's HD 4000....