Wow.

In unoptimized systems it often is purely a matter of optimization, because code that's never been optimized often has some really expensive hot paths in it that slow things down a hell of a lot, because there was lots still to implement and getting that working at all was more important than getting the rest fast.

An example: I sped up the userspace daemon used by the entropy key hardware by more than 1/3rd (minimal figure) or more than 95% (maximal figure) last night. It took about an hour. This is not because the ekeyd authors were fools or lazy: it's because they had other things to do than optimization, so the first person to optimize it could get major speed improvements with very little effort and a few algorithmic changes to a couple of hotspots. (If the structure of the code is such that such changes are unnecessarily hard, that *is* an indictment of the original developers. This certainly wasn't true of the ekeyd and I doubt it's true of Rakudo.)

I would *expect* developer prereleases of software to be just like this more often than not.