this is a Misunderstanding
HDMI is the bandwidth digital signal bandwidth, VGA analog signal bandwidth, the two are different definitions. they are Can not be directly compared. Two different technologies as a means of transmission, broad bandwidth comparison does not make any sense. If to compare, it can transmit the same resolution in the case to compare, for example, high-definition, the need HDMI 2.2 GHz bandwidth, and VGA only need 172 MHz bandwidth. Why are there so that the middle of the difference?
HDMI is the first digital signal, when analog video signals have a pulse, HDMI will need a group of 0,1 square wave signal encoding to describe, of course, need the bandwidth is much higher.
But it does not mean that HDMI high-bandwidth transmission of video signals more, but this is only because the transmission technology is different.