Question regarding higher frequencies of RAM

This is the second month I can't decide whether to sell your memory and go to much higher frequencies. Reznova of course the frequency of operatives much like percents and Vice versa, the higher the frequency of the plank, the more fps and more performance potential will give the Central percent. I have learned from a close friend. The difference, of course there is!
But with regard to Intel-but, in reality, did not have such experience, and all information is only tuboscope source. This is not enough to make the right conclusion.
If anybody had any experience with operatives, that is, was there a noticeable difference in performance between the transition from 3200-3300 on frequency 4000Мгц and above???
The only Intel platform that was.
And was there a significant difference in benches?????