Question / Help OBS Lagging after 15min of streaming

[Sparkules]

OBS starts lagging after ~15min of streaming and after 45 - 60mins, my gamesound (waveout) is lagging behind.
im streaming my xbox one with a capture card(hd60pro).

https://drive.google.com/file/d/0B39ApPMrvlMESmJDb016Y1NaaUU/view?usp=sharing