That was not actually 4K. GT5 actually runs at 1280 x 1080 rather than 1920 x 1080. That means the actual resolution in that demo was 2560 x 2160 (5,529,600 pixels)...an entire 1920 x 1080 screen short (2,073,600 pixels) of true 4K resolution: 3840 x 2160 (8,294,400 pixels).
I'm not trying to say the demo didn't look impressive but I don't like seeing false notions thrown around like facts. That was not true 4K resolution.
The rEVOLution is not being televised