Index of Coincidence: Modern Computer Update

Update to my Index of Coincidence “Modern Computer” testing with some other languages.

I brute-forced Enigma rotor settings in C, Rust, Swift, and Metal on an M4.

Single-threaded, Rust and Swift both land within 6-9% of C when you disable bounds checking. Leave the safety on, and there’s a real performance gap. Turns out billions of array lookups add up.

The Metal GPU completed the entire 5.9 million-candidate search in 27 milliseconds. 67x faster than single-threaded C and 2.5 days faster than my beloved Commodore 64.