There’s also Intel’s Xeon Phi boards with 72 cores. I suppose the more interesting thing though about Connection Machines was the routing though, something that Intel solves with a reasonably standard ring bus.
Indeed. This part of the article goes into it, including Feynman's participation: http://www.mission-base.com/tamiko/theory/cm_txts/di-ch2.htm...
While I worked at the Naval Research Lab they acquired a series of these machines as they came out. They were very fast for "embarrassingly parallel" problems, and problems where computation dominated communication. I published a few papers on shocks and detonations in crystals from simulations using these machines. They used a language called "C*" that was C with parallel extensions specifically for the CM.
I've had a very long term personal pet project of social simulation. Multi-Agent sims are really well suited for systems with very many independent cores (threads); that's why I was interested in the Epiphany. Seeing the Phi selling for something like $200 is really, really tempting. However, I hesitate because not only is the most of development that's gone on for the Phi so far really different than what I've been doing, the next version of the Xeon Phi will be self hosting (so it will be in a regular processor socket in a regular server motherboard). So I expect the prevalent software architecture to change again and the PCIe based versions will become a sort of evolutionary dead end.
Still... I have a Haswell based development box which would support the Phi so it's really tempting! My secret hope is they begin to surface on eBay from folks who impulsively buy them only to discover they don't have a system which actually supports it and whatever they thought they were going to do isn't worth buying additional hardware.