[derac]

You can run many programs on one supercomputer simultaneously, yes. Check out XSEDE. Cost-wise one big is going to be cheaper than 8 small due to infrastructure issues - cooling, maintenance, space, etc.

[pphysch]

"XSEDE" proper is getting EOL'd in a couple months and transitioning to ACCESS [1].

[1] - https://www.hpcwire.com/off-the-wire/nsf-announces-upcoming-...