Set 45 on all cores for multiplier to get 4.5ghz boost on 6600k on Z170-A motherboard with adaptive offset + 1.35V. Works perfectly fine with no modifications to OSX, Reflects boost speeds in hardware monitor on my toolbar right out of the box, also have XMP enabled 3200mhz Corsair LPX. All works fine. Not sure how you guys are having issues as i've made no modifications to the OS.
You used the unlocked multiplier to OC, which is working just fine. Overclocking via the BCC Clock is not working. I switched to a 6600K, and I'm currently running it at 4.4GHz.
I didn't have Enable P States checked in Clover Configurator.