I plan at some point to implement some benchmarks to test exactly that. I have the feeling that the gain is not going to be as significant as I initially expect

I plan at some point to implement some benchmarks to test exactly that. I have the feeling that the gain is not going to be as significant as I initially expected. Rust is pretty good at optimizing fat pointers. Though another advantages to word-width objects is that they can generally be used in atomics, whereas sizes greater then a word usually can't. Do you have a link to your hobby interpreter? I would love to take a look at it.