I have a Hyper 212 Plus and I was able to hit 4.5ghz stable. The Artic Pro might be a little smaller but like previous poster said, you should be able to hit 4-4.2ghz.
As far as OC, do the following to yield the best temps.
offset leave it a +0.05
Intel Turbo Boost increment one notch at a time. Begin with +0.04 and work your way up.
Load Line Calibration (LLC) leave it on either 50% or 75% (Level 2 or Level 3)
Spread Spectrum Disabled
Everything else on Auto
Each increment run Prime95 Blend for about 15 min.
Using this method I was able to OC to 4.5ghz @ 1.186v with temps not going over 77c after many hours of full load on Prime95.
let me know if you have any more questions.
Well ill try to get 4.1 tomorrow, cant i just leave the voltage the way it was before? just change the multiplier, thanks for your answer, rly helped me out