Ciel (DayZ)

Like explained in the Topic my game keeps flickering like crazy. I tried playing arround with the grafik setings but nothing helped. I Also made a video using fraps to show what im talking about. If anyone have a solution for this or what causes this i would be very thankfull. Heres the video :

i simply want the get rid of this flickering stuff which is not normal. And besides since when does better grafiks increase ur aiming? Oh wait i forgot its an old rule of pro gamers which play only in rl grafiks.