> why does a serial bus require 24 pins It turns out to be cheaper and easier to aggregate multiple serial links than to run a wide parallel bus. Practically e

> why does a serial bus require 24 pins It turns out to be cheaper and easier to aggregate multiple serial links than to run a wide parallel bus. Practically every modern high-speed interconnect uses multiple aggregated serial links -- USB, Ethernet, SATA, PCIe, DDR3+, DVI+HDMI+DP+LVDS, etc, etc. > why can’t we just switch to optical cables already Too expensive. A big part of USB's dominance in the mid-90's was that it was way cheaper than the alternatives of the time. Thunderbolt was originally designed for optical interconnects. > Just use the 3.5 mm audio plug It's physically too large for current and upcoming designs. I miss TOSLINK.