Just read their new 10 core chip will hit 5.3ghz which is pretty sweet makes me wonder if they tweaked their turbo a bit more.Clocks alone are meaningless. Throughput = IPC * clock. If you have 30-40% more IPC at 4GHz in typical workloads, you get per-core throughput equivalent to the old chips at 5.2-5.6GHz, usually at a lower energy cost.
Intel should start doing chiplets like Amd, their was a rumor they tried awhile ago but didn't go with it.
Edit also i know IPC is king and it will matter more and more coming in the future with 7-5nm limiting clock speeds.