Normal map problem

[Rudgary]

Hi everyone! To be short, when I am applying too much bump(more then 1), I start seeing mesh wire on my renders, like smoothing groups stops working in some places. I have uploaded reference img and part of the normal map, also you can see my node setup. As a bitmap I am using .exr. I have tested .jpg and .png. Result is the same. Also I tested it using different modifiers  (Turbosmooth, Opensubdiv and Meshsmooth).
I would like to be able to have more control over bump strength but because of that, maximum of what I can effort is 0.8-0.9.