Provide a simple optical fiber transmission without cumbersome 5V power cabling
Optical fiber cabling is usually required on DVI interface when you need to transmit more than 5 metres. In that case, 5V power is required in order to change the signal to optical from electric. There are two ways to supply the 5V power, the first way is from AC-adaptor, and the second way is from DVI-D connector itself.