It depends on how the players offload the files. Some players can offload it to GPU (if it have specific format hardware decoding support), some use the CPU to

It depends on how the players offload the files. Some players can offload it to GPU (if it have specific format hardware decoding support), some use the CPU to do the processing. Check your player setting and see which one it is using. My MPC-BE player will tell me if the player is using the GPU to decode. And at the same time, it depends on if the file have 8-bits or 10-bits. Some CPU/GPU don't have the support for 10-bits which can offload it to the software decoding which can be resource intensive for your system to decode the file at the software level.