why does an unchanging monitor receive 6GB of data every second across a big fat cable?

Why does an unchanging monitor receive 6GB of data every second?  The exact resolution and refresh rate and color depth do not matter (the above is for 8k@60Hz with 24 bit color): the point is, if the picture isn't changing, wouldn't a better rate be approximately zero, rather than being a very high amount?

The full frame data is sent with every frame.  It's mad.

With some remanence in the monitor, just updates could be sent.  Nothing complicated.  Initially it could just be "picture changed here's full frame".  Then, in cases where picture no change, not much data need be sent.  Can improve on this, but keeping in mind keep it simple, and keep it suitable for hardware.

The hdmi (or whatever) PHY at the computer end, plus the cable, and receiving terminal at the monitor, can all be seen as part of the system driving a volatile hardware panel, but a system notionally internal to the monitor.  So you want a box that can do this and attach to the back of the monitor and pretend to be part of the monitor, and a protocol for talking to that box, and a computer that outputs that, and things are starting to head in the right direction.

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