And, with more work, that's true of computers in general; they can all do the same computations once you somehow wire up enough memory: https://dmitry.gr/?r=05.Projects&proj=35.%20Linux4004
For chess though, there are time constraints. The 386 is a lot slower. Is it fast enough?
An 80386 is about 10–13 Dhrystone MIPS, while a 200MHz Pentium Pro is about 90–450, according to https://netlib.org/performance/html/dhrystone.data.col0.html. So we're talking about a further slowdown on the order of 20×. I don't know how to estimate how much that would lower its Elo.
The article says:
> By making a number of adjustments to the algorithm and tuning it to the Pentium, we can increase its Elo to 2846 ± 35 at 1 second per move, 3109 ± 79 at 10 seconds per move, and 3180 ± 80 at 30 seconds per move.
So making it 30× faster would raise its 1-second Elo by about 334 points, and ln(30) is 3.4, so that's about 100 points per factor of e. ln(10) is 2.3, so we'd interpolate a prediction of 230 points gained at 10× faster, reasonably close to the 263 points reported.
If we extrapolate that in the other direction, ln(20) is 3.0, so on the 80386 we'd expect a loss of about 300 Elo points, down from 2846 to 2550 or so. Still enough to wipe the floor with Crafty, but low enough that Kasparov would usually beat it.
But we don't really know if that extrapolation is valid.
A common rough rule of thumb used throughout the 2010s (because it no longer holds) in computer chess was that a 2x speedup gives about 50 Elo. This mostly holds in that region but at low levels it is more like 100-200 points.