Well, if we define a reasonable yardstick for this, and try to write idiomatic code without low-level hacks and optimization, Rust has the potential to be faster because its more strict aliasing rules might enable optimizations that the C compiler wouldn't try.

However I remember reading a few years back that due to the Rust frontend not communicating these opportunities to LLVM, and LLVM not being designed to take advantage of them, the real-world gains do not always materialize.

Also sometimes people write code in Rust that does not compile under the borrow checker rules, and alleviate this issue either by cloning objects or using RefCell, both of which have a runtime cost.