startup.js

const cp = require('child_process');

const INNER_LOOP = 50;
const OUTER_LOOP = 10;


function timeNodeStartup(times) {
    const ts = Date.now();
    for (let i = times; i > 0; --i) {
        const result = cp.spawnSync(process.execPath, ["-e", "0"])
    }
    return Date.now() - ts;
}

const times = Array(OUTER_LOOP).fill(null).map(_ => timeNodeStartup(INNER_LOOP));
console.log(times);