Because you are currently playing your Pro on a plasma TV and claiming to be outputting "the same" but NO plasma TV accepts a 4k input. You are therefor playing the PS4 pro at 1080p and that does not stress the console enough to ramp the fan up. I can hook my pro up to a 1080p monitor and yes it's quiet. You originally disagreed with me and other users when we said the pro is loud when outputting 4k CB (checkerboard) and HDR. If the pro is only outputting FHD (1920x1080) and doesnt have "boost" enabled it does not get hot at all.