Interesting question - it’s not trivial to find a metric that’s directly comparable between a 486-era chip and a modern x86 chip. MHz isn’t the whole story, as modern chips have multiple cores and greatly improved instructions-per-cycle. Synthetic benchmarks like Whetstone might provide a point of comparison, but it’s hard to be sure the different benchmarkers were running the same version.

Wikipedia says the 386SLC from the article drew 2.5W at 25Mhz. A Ryzen mobile CPU draws something like 15W. My gut says the Ryzen is a lot more than 6x faster.