Unfortunately not, from the sources that I've seen the Intel i7 8086K is actually a 4.0Ghz base CPU, with a 5.0Ghz boost frequency - it's not clear if it's an all core boost, or a single core boost, but judging on how intel CPUs are currently, I think it's a single core boost.

If that is the case, the AMD FX-9590 would have been the first 5.0Ghz CPU as it had a 4.7Ghz base clock with a 5.0Ghz Boost . That said the frequency didn't save this CPU from being a terrible CPU in general, as were most of the Bulldozer/Piledriver CPUs.

Seems like we've still got to wait for a retail 5.0Ghz all-core CPU (not including custom overclocks that is).