Comment by username223

> What sort of crazy experiments would that have spawned?

Scientists then (at least a lot of them) knew what they wanted to do, and it required faster computers rather than more of them. A lot of that Cray power at the national labs was doing fluid simulation (i.e. nuclear explosions), and with the computers they had in the 80s, it was done in one or two dimensions, relying on symmetry. Going from n^2 to n^3 grid cells was the obvious next step, but took a lot more memory and CPU speed.