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

Maybe not in this exact case but the way I imagine more data going through the same cable is like audio. The basic technique is to put many streams of data on the same wire at the same time.

My analogy is audio, if you were to “listen” to the slow data rate you would only hear one tone but for a higher data rate you would hear two tones at the same time or more. As the years advance so does the hardware and it’s ability to pick out the different tones and separate them out into the data they’re actually carrying.