[dependencies]
crypto = "0.2.36"
rayon = "1.8.0"

extern crate crypto;
extern crate rayon;

use crypto::digest::Digest;
use crypto::sha2::Sha256;
use rayon::prelude::*;
use std::time::Instant;

const NUM_HASHES: usize = 1000000;
const NUM_THREADS: usize = 4;

fn compute_hashes() {
    let string = "sha256_maxhash".as_bytes();
    let mut sha = Sha256::new();
    for _ in 0..NUM_HASHES {
        sha.input(string);
        let _ = sha.result_str();
        sha.reset();
    }
}

fn main() {
    rayon::ThreadPoolBuilder::new()
        .num_threads(NUM_THREADS)
        .build_global()
        .unwrap();

    let start = Instant::now();
    (0..NUM_THREADS).into_par_iter().for_each(|_| compute_hashes());
    let duration = start.elapsed();

    let total_hashes = NUM_HASHES * NUM_THREADS;
    let hashes_per_second = total_hashes as f64 / duration.as_secs_f64();
    println!("Time taken: {:?} seconds", duration);
    println!("Hash rate: {:.0} hashes per second", hashes_per_second);
}

time for a in $(seq 1 10); do echo "$a" | sha256sum; done

*-cpu
          product: Intel(R) Core(TM) i5-6300HQ CPU @ 2.30GHz
          vendor: Intel Corp.
          physical id: 1
          bus info: cpu@0
          version: 6.94.3
          size: 2660MHz
          capacity: 3200MHz
          width: 64 bits