Isn't that expected? 4K Blurays only encode up to like 128Mbps, which is 16MB/s. 100MB/s seems like complete overkill.

It isn't for the amount of motion involved. Third person views in rally simulators and continuous fast flicks in shooters require it

I think op just didn’t type Mbps properly. 100MB/s or ~800Mbps is way higher than the GPU can even encode at a HW level even I would think