Due to Rust's concern about thread-safety, the standard println! macro acquires a lock prior to writing to stdout. This means that if you're doing a lot of prin

Due to Rust's concern about thread-safety, the standard println! macro acquires a lock prior to writing to stdout. This means that if you're doing a lot of printing, it can be quite slow due to the extra work of acquiring and releasing that lock. This is fairly well known and if it's a bottleneck in your program the recommendation is to acquire the lock yourself and then write directly to stdout.