OBS preview low fps

[Tauwer]

hey guys,

 

when i try streaming games like assassins creed IV the in game fps is normal but my preview on obs is just stuttering all over the place.

when i see the stream on a different machine via twitch, it`s fine just normal 30fps 720p what i tend to output.

why is the preview stuttering and how do i fix it?

 

system: Gtx 960 4gb

R5 1600

8gb 2133

350w system power be quiet

b350M A asus motherboard

 

thanks in advance