would reprojection feature be affecting this? should it be on or off?

thanks i have a AMD ryzen 3600 + GTX 1070. am i tech limited?

so i can watch smoothed SVP for regular 1080p h264 movies fine in Simple VR player (like DeoVR but better imo) , but whenever i choose 6k (2880p+) files it doesn't smooth it.

SVP detects it and even i can see processing resources being used (but not maxed out, ~60%)

furthermore, H265 6k videos just won't get detected altogether

anyone know why this is?