The Cost of a Supercomputer

When does a computer become a supercomputer and do publicly purchasable personal computers surpass the capabilities of the first slash early supercomputers? If so, how much would it cost? By the way, that is a tongue twister. There's a lot of P's and C's in that one. And we might even be able to recommend a pill at some point. But probably not. Even with that still pending, this is a ding. Yes. Ding. Have a ding look for your mat.