Playback from hard disk or DLNA (LAN) can only support up to 1080P resolution.  Playback from HDMI support HDMI 1.4 4K but not HDMI 2.0 4K. The HDMI 1.4 specification supports 4K formats: 3840 pixels wide by 2160 pixels high @ 24Hz | 25Hz | 30Hz 4096 pixels wide by 2160 pixels high @ 24Hz