The 9% increase in clock speed paired with the 17% increase in memory frequency, plus the other efficiency improvements the Ivy Bridge architecture provided over Sandy Bridge, allowed the Core i7-4960X to provide 17% more memory bandwidth than the i7-3960X. With a total bandwidth figure of 39.79GB/s, the Core i7-4960X blew everything out of the water and almost doubled the bandwidth of the i7-4770K.
While we saw a massive improvement in memory bandwidth performance, the cache performance gains were only very minor. With around 20MB/s more performance for the L1 and L2 caches the Core i7-4960X was around 4% faster. That gain can be mostly attributed to the increase in clock speed. When compared to the Core i7-4770K the i7-4960X provided significant improvement for the L2 cache, while the L1 cache was worlds slower.