I remarked in my future OS post that we should standardize on one digital interface format for everything digital. One way to solve the most pervasive problem in that domain (that the bandwidth use cases of devices differs quite a bit) can be solved with dynamic frequency clocking of the interface buses. An easy way to solve this is to have a hot-plug handshake between devices - when a connection is made, each side sends standardized information about itself (what it does, what frequencies its capable of, etc) and the interface uses the lowest frequency both support that sufficiently fills bandwidth requirements of the interconnect. So you could in theory have a multi-gigahertz interconnect where low bandwidth devices (like input devices) could run at only a few hundred hertz.
Some general numbers:
The most bandwidth intensive activity I can conceptualize for this interconnect, besides just going all out maximizing the bandwidth for usage as a supercomputer interconnect, is about 10 GB/s or 80 gb/s. I get this number using 16:10 Ultra-HD at 48 bit color depth (12 bits per color channel + 12 bit alpha channel) at 180hz (this comes from the idea of using 3d displays - 90hz is a good standard that most human eyes can't differentiate very well, just like 4k is a good resolution where most eyes won't see the difference at 250 PPI from a distance of 2 feet - I wouldn't ever use a 3d display, but the standard should anticipate that). Given that current Displayport can reach 18gb/s, increasing that 5 fold in time for this "concept" to actually matter is completely feasible. Worst case scenario, you just include more packet channels. Comparatively, we have pretty much clobbered the limits of audio and codecs like Opus just make compression even better over time, so I'm not worried about 15 speaker surround sound being the next big thing.
But just as a consideration, if you were to go completely audio-phile crazy and used 20 mbit/s lossless audio on 33 speakers. That still only constitutes 660 mbit, less than a gigabit. In practice, if you are transferring raw video without some kind of encoding compression, it will be the absolute dominator in bandwidth utilization.
So a target of 10GB/s sounds good, especially considering that also works as an interface bandwidth target per lane inside the chip architecture. If running at peak throughput, you would be effectively running a cpu-northbridge interconnect over a wire.
If we use fiber channel for this connector standard, it can be the ultra-low-latency needed to be as multi-purpose as it needs to be. However, while it could be ultra-high bandwidth with low latency when needed, you could also disable all but one data channel and run it at a few hundred hertz for a few megabytes of bandwidth, which is also a keyboard or mouse should need.
I could also see color coded cables indicating the peak frequency on the line supported - a 100' cable probably wouldn't be able to run at whatever frequency is needed to supply 10GB/s without active modulation, whereas a 20' cable should be able to. This also means it makes a good ethernet standard, because realistic network bandwidth won't pass a gigabit for a long while, and getting a gigabit on a multiplexed cable like this will be cakewalk at really low frequencies.
I really don't even want to consider analog interfaces with this configuration. It should be all digital video, audio, etc. You could always stick an analog converter chip on top of this interface like a traditional PCI device anyway.
I also would only want one standard connector, preferrably as small as possible, with an optional lock mechanism. Just from my personal view on the matter, but having 3 standards of usb, micro usb, hdmi, mini hdmi, micro hdmi, mini displayport, displayport, etc is just absurd. If the maximum connectivity can be obtained on a smaller connector foot the extra few cents to build a better circuit.
Just as a footnote, real world 100gbit Ethernet should eventually hit market, and that would be the perfect standard for this.
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