Mac OS strange perfomance drop

Even Macbook with Intel HD can run 60 fps+ stable, but the problem is a some kind of pipeline. When there is alot of Effects, the game is running stable 60 fps, but it stutter and feel like 30 fps. Why this happend? It's looks like game can't display so much effects on Mac OS (OpenGL?).

Using windows -- 0 drops. [sg-ahri-1]