[deschutes]

To my understanding there is and there isn't. The driving force behind this demonstrated that it was possible to speed up the existing CPython interpreter by more than the performance cost of free threading with changes to the allocator and various other things.

So the net is actually a small performance win but lesser than if there was no free threading. That said, many of the techniques he identified were immediately incorporated into CPython and so I would expect benchmarks to show some regression as compared with the single threaded interpreter of the previous revision.