Rosetta does quite badly with JITed stuff (notably, it does very, very badly with x86 JVMs). I assume it'll be fine once native Unity is available.

Huh, this is surprising to me. Anecdotally, I tried Minecraft Java under Rosetta on my MBA, and it ran smoothly 2560x1600 resolution at 60 FPS with very few drops. Although I'd imagine that a JITed game might be easier for Rosetta to deal with, as it will be running the same code paths over and over again in comparison to a compiler.

I’ve never played minecraft, but is it generally cpu bound? The GPU is very fast, for a laptop-y thing, so that may be carrying it.

In synthetic tests, Java under Rosetta seems to range from twice to over four times as slow as native arm Java, depending on workload.

The linked article with the benchmarks doesn't make it clear what JVM is being used. Since the Java benchmarks seem to perform well, I assume they're using a native JVM?

Yeah, looks like it. It say they're using Azul's one, and that's available for MacOS ARM64.

Yeah I just imagine that its a worst case scenario for Rosetta there. Possibly a lot of SIMD that isn't getting translated to neon simd.