Hi,
The resolution looks to be 640x480. In his resoltuion, the loading should be tiny and hardware converter can handle it to achieve target performance. If you use higher resolution such as 3840x2160 and hit performance issue, please refer to this post:
Nvvideoconvert issue, nvvideoconvert in DS4 is better than Ds5? - #3 by DaneLLL
To run hardware converter at max clock always.