Samsung Tomorrow (Flickr): What is ultra definition? UD for short, it packs a 3840×2160 pixel format. From 1920×1080 double the pixels horizontally and vertically and you get ultra definition. Samsung showcased a 70-inch ultra definition 3D LCD TV and runs at 240Hz. The company developed a high speed silicon interconnect based on oxide semiconductor technology to update all those pixels quickly enough for 2D as well as 3D.