Setting up two capture device (game capture card + webcam) in the same scene takes too much cpu usage

[Rainsspark]

Been having this problem that whenever I stream with my webcam on, it cpu usage skyrockets, frames play around in 51-58fps and the encoder overloads every now and then but it becomes stable when I turn off the webcam. Should I capture the webcam in a program like vlc/splitcam/manycam to help ease the problem? Any tips will be appreciated.