|is it possible to hit 4ghz on stock cooler?|
First of all what do you mean by "stock cooler". I made a "leap of faith" that you were talking about the HSF that comes with AMD CPU's for example.
If not, please tell us what you mean.
If you have a question about whether or not the Noctua NH-D14 can cool, legitimately cool over extended runs, it might be better to start your own thread. From what I read and I read probably more than most, the Noctua is your best bet. Pseudo Liquid Cooling units like the Corsair H-50 and its iterations are no match and should be considered toys. (Corsair is, however, one of the very finest companies out there, second to none!)
Other units recommended because they fit over Corsair Dominator and GSkill will probably do OK. But the Noctua is a Beast; it's not cute and it's not pretty - but neither are the NFL linemen who protect Peyton Manning.
Really want to know. Please feel free to post your HSF questions in the proper thread. This is a motherboard thread.
(Note: I mistakenly posted a similar question in what I thought was the relevant thread, when I first joined OCN, and got a rap on the knuckles from an Admin for Thread Hijacking. Like you, I sure thought I had done nothing wrong at the time.)