Kcd is pretty much cpu dependant and with that gear you should definitely get 60fps or more on 1080p. Try 1440p res. If it runs the same then the cpu is limiting. Check that you have hyperthreading and all the cores enabled in bios and also check those other power limiting settings in bios. You can run msi afterburner on stock gpu settings but enable all the cpu cores (all 16 of them with hyperthreading enabled), clocks and temps for the monitoring also. That might give a hint of whats going on. HW info program can also give useful info if something is throttling. Intel extreme tuning utility is useful too to run a quick stress test for cpu&memory. Try enabling memory xmp profiles from bios too if not already. Set windows power plan to high performance also.
Here is some video about those power limiting settings. Starting at around 17:00. Not the oc settings before that. Be careful if you’re not sure what you’re doing. Might end up damaging your system. Especially voltages can damage your cpu and some asus stock settings give too high voltage for the cpu but again I would advise that you learn what these do before tweaking. That is if not already familiar with all this.