Hi! I'm currently evaluating what hardware that is needed to run a high bitrate, 50 fps 2160p (3840x2160, UHD, 4k, what you want to call it) encoded with either ffv1 or h264-lossless. I tried it on several computers, both OS X and windows (and linux) and nothing I've encountered yet have managed to play it out even on 24fps. The encoded bitrate (using ffmpeg with llv1 or libx264 -crf 0 or 1, with -pix_fmt yuv420p so it is chroma subsampled.. "easy" ) is more than 2 Gbps, so quite taxing. If someone would like to try it I could provide you with either the encoded file (~3GB) or a link to the online .png-files with command line encoding settings.