If all HDMI cables are basically the same design, pinout, etc. how have they been able to double, quadruple, etc. the bandwidth on them over time?

Question

Going from HDMI 1.4 to 2.1 there is a 5x increase is bandwidth. Is it because the cables themselves were never the issue but it was the connectors/chips in the devices themselves that couldn’t handle it?

I know part of it is the actual quality of the cables themselves and tighter tolerances, more twists in the wires, material purity, etc. but I can’t imagine that alone would be enough to fully account for this.

In: 565

Answer 1

They are not the same, there’s variation on the thickness of the cable, shielding and materials so we have various standards that define the maximum bandwidth a given cable supports so while a 2.1 cable has the same amount of wires as a 1.4 they are constructed differently and the 2.1 has better quality. All of this assuming said cables actually comply with the standard.