"I'm calculating to see when my PC would have been the fastest on Earth. It looks like in 1992 it would be able to out-compute the latest Dept of Defense $90m supercomputer that filled an entire room, would you believe?"
"That's lovely. How will that help us pay our credit bills?"
Jesting aside. There is a bunch of data for this, like this set here:
https://en.wikipedia.org/wiki/TOP500
And if you extrapolate backwards or find older data, like I did, I came to the conclusion that if I took my PC back to 1981 it would actually be faster than every computer on Earth combined, or some insane statistic like that.