I think I can chime in as I guess my CPU is close to yours, a 3930K at 4.4 and per some benchmark site the numbers are very close to an 4.8 clocked 8600k.
Depending on the scenery my frames drop to below 60 and sometimes below 50, but that needs an open space like some angles in The Pit where all the horde waves are coming from roughly the field of view, or something similar.
Our graphics settings are quite different and I am running a 1070 (which I doubt makes just about any difference).