I think https://github.com/quick-lint/cpp-vs-rust/blob/f8d31341f5cac... indicates Rust is using Mold too. And I get the impression that the thing unit being benchmarked is a single crate—that is, one crate 8×, 16×, 24× the size (which puts the burden on the compiler, in areas that don’t parallelise well), rather than 8×, 16×, 24× as many crates (which puts the weight on the linker and on well-parallelised parts of the compiler).

On the hardware in question, which has loads of cores, I’m very confident that Rust would fare considerably better with 24 17.1k-line crates (410k lines, larger due to duplicating the entire thing rather than just the lexer) than with the one 104.4k-line crate apparently tested.