I'd like to get a better sense of how well hyperthreading works in practice on stuff like this. Is it really the case that my physical cores' pipelines are < 50

I'd like to get a better sense of how well hyperthreading works in practice on stuff like this. Is it really the case that my physical cores' pipelines are < 50% utilized by video processing, such that the hyperthreads are equivalent to having a whole other core? Because I'd have guessed that, IO aside, you really want slightly fewer processes than virtual cores.