The article cited by The Register cites this more detailed analysis in return: blog.katanaquant.com/…/your-llm-doesnt-write-corr…

Performance of the AI-generated version was 20,000 times slower on one specific benchmark, but “only” about 2,000 times slower when averaging over multiple different benchmarks (which is, imo, a better measurement of the code’s quality).

So I suppose The Register pulled from multiple sources (as you should) and just linked to the most top-level of all of them.