Both double as space heaters unless one delids them which wipes the Intel warranty
So be aware of that oc'ing is sort of limited on all x series including Kabylake too.
After a delid and you still need a pretty good liquid cooling system to really oc
I've personally only gone to 4900 @74c I believe it was
Before I was hitting thermals of 97c at only 4644. or 46 all core on a 7900x that was using a Corsair H115i.
I now use a EK-280 performance loop kit all is in my system spec'sEdited by ThrashZone - 11/17/17 at 7:35am