CPUs can do pretty much anything, but not so quickly. GPUs can do a limited set of computations, but they're highly parallel vector/matrix processors with massive memory bandwidth. So for those calculations that they can do, they are vastly more powerful than a CPU. Check out the Folding@Home site and see the relative speed of the GPUs involved in the effort.
GPUs can do a limited set of computations, but they're highly parallel vector/matrix processors with massive memory bandwidth.Is a GPU effectively an array processor, or suchlike?
That's what I sort of suspected, from what was being said. My experience of twenty years ago was that that sort of thing was an expensive special purpose box about the size of an old PC system unit. Called an "array processor." Why would I expect that something which was the size of a PC back then would take any more than a board, if not indeed a single chip, today!