IIRC what some were saying, the implementation in Rust and the implementation in C for some examples were completely different algorithms. .... Actually, yeah, looking at the Rust and C implementation of the "reverse-complement" example, you can see that the Rust implementation is using some sort of CPU feature detection hacks and the code looks a lot less idiomatic in general than the C implementation. Rust: https://benchmarksgame-team.pages.debian.net/benchmarksgame/program/revcomp-rust-1.html C: https://benchmarksgame-team.pages.debian.net/benchmarksgame/program/revcomp-gcc-6.html So yeah "faster" than C indeed.