[loic-sharma]

https://blog.heroku.com/ruby-3-by-3/

[norswap]

Fair warning: this is from 4 years ago.

[eregon]

That's rather vague. But yes, no matter which JIT you always need some extra memory to run the JIT, and it creates a more optimized version while also needing the unoptimized version of the code, so it needs more memory.