FullHD and core i3-3217U:
Video: MPEG4 Video (H264) 1920x1080 60fps [V: h264 high L4.2, yuv420p, 1920x1080]
Audio: Dolby AC3 48000Hz 6ch 448kbps [A: ac3, 48000 Hz, 5.1, 448 kb/s]
MPC-HC:
Overlay in Window(zoom50%) = 25% CPU load
Overlay in Fullscreen = 28%
EVR Custom in Window(zoom50%) = 40%
EVR Custom in Fullscreen = 35%
For comparing this video with internal win10 application "Movies & TV" gives 8% CPU load in window and 7% in Fullscreen. Compare to yours results.