js sequence vs. parallel

js_sequence_vs_parallel.js

(async ()=> {

    const TTL = 1000; // ms
    const N = 4;

    const foo = () => {
        return new Promise((resolve, reject) => {
            setTimeout(resolve, TTL);
        });
    }

    // Sequence
    let start = Date.now();

    for (let i=0;i<N;i++) {
        await foo();
    }

    console.log(`Sequence took: ${(Date.now()-start) / 1000} seconds`);

    // Parallel
    start = Date.now();

    const promises = [];
    for (let i=0;i<N;i++) {
        promises.push(foo());
    }

    await Promise.all(promises);

    console.log(`Parallel took: ${(Date.now()-start) / 1000} seconds`);

})();