Our Handbrake test only shows a slight performance improvement when using the Core i7-5960X as opposed to the 4960X and 4790K.
When running the x264 HD Benchmark the Core i7-5960X was found to be 12% faster than the 4960X and 34% faster than the 4790K.
TMPGEnc Video Master Works was able to utilize all 16 threads, though only seems to utilize each at around 20% or less. As a result the Core i7-5960X was actually quite a bit slower than the 4960X, we suspect this software needs an update to better utilize the 5960X.