Photons are still a lot faster than electrons. Latency at the endpoints is still a thing, but this allows a lot of 800 Gbps channels along distances copper can't match.
I don't want to think about the NUMA model for a beast that takes this to its upper limits.
What is the class of problem that can be solved by computers of a certain size (compute density metric)? If a computer is basically instantaneous, but has to communicate over vast distances, it still couldn't solve large problems.
Couldn't we have already made 100k core single image OSs running over RDMA?
I'm sure that, as we extend the capabilities of our machines, we'll find new problems or approaches to known problems that were not practical up until then.
Like I mentioned, this can increase bandwidth and reduce latency between system components, making warehouse-sized computers look like container-sized ones. I bet we can find some use for that.
I don't want to think about the NUMA model for a beast that takes this to its upper limits.