[TZubiri]

Before IBM's deep blue, apparently there was a chess program called Cray Blitz, I'm sure the cray had the raw power(20MHz? But with 64 parallel operations) needed to beat the top humans, but the software just wasn't there yet.

Blitz was ported to C and continued development FOSS as Crafty, mainly by a U of Alabama professor, but to this day it can't beat top humans on modern cpu (topping at 2650 elo instead of 2850 of, say, carlsen.)

[Mr_Minderbinder]

The latest version of Crafty has a significantly higher rating on CCRL than Fritz 10, the version that defeated Kramnik in 2006. He was the World Champion and was rated 2750 at the time. I do not know what source you used for Crafty’s rating but ratings from different lists are not comparable. It is highly probable that Crafty running on a Ryzen could defeat any human.

I am also of the opinion that with an optimised program the CRAY-1 would have been on par with Karpov and Fischer. I also think that Stockfish or some other strong program running on an original Pentium could be on par with Carlsen. I am not sure if Crafty’s licence would count as FOSS.