I wonder if this is merely an advantage of Intel's larger process size. It seems a threshold has been crossed at 14nm or 22nm where the smaller sizes can't be driven at higher clocks because of voltage and heat dissipation issues. So AMD is forced to trade clocks for cores, whereas Intel's larger (and very mature) process sizes can sustain higher frequencies.

For the most part it's a worthwhile trade for AMD because you get much greater overall compute power with only marginally diminished frequencies, but it's still something for Intel to hang its hat on in benchmarks.