Rust isn't inherently faster than C, but it can be easier in some cases for the optimizer to optimize Rust code better than C code. In particular, I have in mind Rust's reference types and the fact that they all "follow LLVM’s scoped noalias model"[1]. You can, of course, get this same benefit in C by using restrict, but most of the C code I've seen makes little use of restrict (and it's quite easy to accidentally alias a restricted pointer, so it definitely imposes a mental burden, even if it's very slight).

Rust's safety model allows you to get the optimization of C's restrict without the footgun. That can be a big win.

But of course, just because something is written in Rust doesn't mean it'll be faster than the equivalent C code. Rust isn't magic, after all.

[1]: https://doc.rust-lang.org/reference.html#behavior-considered...