On Windows 10, I have an NVIDIA GTX 970 GPU, and a 4 core Intel CPU.
When I play a video up to 4K (any codec, any player), the GPU usage increases a little (about 10%), and CPU usage stays pretty much unchanged; everything runs quiet and smoothly.
But, if I play a video larger than 4K (any resolution larger than 4096 × 2160, no matter if it's just a few more pixels) then the GPU stays idle and the CPU usage increases up to 98%. This results on a choppy playback and a loudly experience as the CPU fan goes crazy.
It seems to me that the GPU has a lot of power unused and should be able to handle >4K videos, but for some reason it refuses to play/decode them, and instead all the work is passed to the CPU.
Is there a configuration / player / decoder or something that would allow me to play >4K videos taking advantage of the GPU?