I had to work on one and didn't really see what the fuss was about. Performance still sucked compared to a Cray2. I mean it was supposed to be a Supercomputer...
I/O was painfully slow so unless you were not planning on looking at your results or your results were a few numbers it may have been ok. We were doing 2d and 3d simulations and periodically outputting large amounts of data to make movies from the simulations. It would run for a few minutes and then stop for several times that to get the data out.
It couldn’t keep pace with a Cray for any tasks that weren’t optimized for its architecture. If your problem fit the SIMD model like the genetic algorithms I was implementing at the time it was just amazing.
Yeah, ours was a fluid dynamics problem that needed information from neighboring cells. So at some point there needed to be data moving between cells and that really killed performance. There was also a global value that need to be computed at each iteration that controlled the simulation speed to ensure the step sizes were not too big.
Also the file I/O was horribly slow. We where scaling and dumping raw data to files so what we could do post processing to make movies of the simulations.
Plus, beyond the fascinating architecture, it was a beautiful machine. The Cray-1 and its successors may occupy more historical memory (see: Sneakers (1992)) but the CM-1, CM-2, and to a lesser degree (in my ever so humble opinion), the CM-5 blow Cray's most iconic machines out of the water on the sexiness axis.
If you're in the American Southeast, the Computer Museum of America in Roswell, GA has one on display. I've visited and seen it, along with other supercomputers.
