Javascript sequential vs parallel promise execution

sequential_parallel_promises.js

const fetch = require('node-fetch')

async function fetchDogsImagesSequential(dogs) {
    const images = []

    for (const dog of dogs) {
        const response = await fetch(`https://dog.ceo/api/breed/${dog}/images/random/3`)
        const data = await response.json()
        images.push({
            [dog]: data.message
        })
    }

    return images
}

async function fetchDogsImagesParallel(dogs) {
    const promises = dogs.map(async function (dog) {
        const response = await fetch(`https://dog.ceo/api/breed/${dog}/images/random/3`)
        const data = await response.json()
        return { [dog]: data.message }
    })

    return await Promise.all(promises)
}

(async () => {
    const dogs = ["affenpinscher", "african", "airedale", "akita", "appenzeller", "basenji", "beagle", "bluetick", "borzoi", "bouvier", "boxer", "brabancon", "briard", "bulldog", "bullterrier", "cairn", "cattledog", "chihuahua", "chow", "clumber", "cockapoo", "collie", "coonhound", "corgi", "cotondetulear", "dachshund", "dalmatian", "dane", "deerhound", "dhole", "dingo", "doberman", "elkhound", "entlebucher", "eskimo", "frise", "germanshepherd", "greyhound", "groenendael", "hound", "husky", "keeshond"]

    const hrstart1 = process.hrtime()
    await fetchDogsImagesSequential(dogs)
    const hrend1 = process.hrtime(hrstart1)

    const hrstart2 = process.hrtime()
    await fetchDogsImagesParallel(dogs)
    const hrend2 = process.hrtime(hrstart2)

    console.info('Sequential execution took: %ds %dms', hrend1[0], hrend1[1] / 1000000)
    console.info('Parallel execution took: %ds %dms', hrend2[0], hrend2[1] / 1000000)
})()