I have a problem with FO4, randomly when i play my sound dies, but im still able to move and shoot , and after some time (20-30 seconds) game freezes for about 20 seconds,

My PC: Downloaded newest graphics drivers, GTX 970, GB RAM, and AMD FX6300 ( 3.5 GHz)

the game set itself on Ultra after the initial scan of PC, but i lowered them for a bit to see if it helps, it didnt