Check out some benchmark results of Intel's Core i7-4960X "Ivy Bridge-E" processor as Asian tech board Coolaler decided to leak them. The chip was compared directy to the Core i7-3970X "Sandy Bridge-E" on an identical system. The conclusion is that Ivy Bridge-E seems to be about 5-10 percent faster than its predecessor.
the Core i7-4960X isn't scheduled to be officially launched until the second half of 2013. However, as the benchmarks, which you can see in the images above and below. 3DMark Vantage (CPU score), 3DMark 06 (CPU score), the Cinebench 11.5, SuperPi mod 1.6, CPU Mark '99, and WPrime 1.63 suites were run.
Overall Ivy Bridge-E is merely 10% better than Sandy Bridge-E.