ALT ~ took 5s ❯ bun-26821 event-loop.js # New 3.82M event loop iterations/sec (19,087,591 in 5.0s) ~ took 5s ❯ bun-1.3.9 event-loop.js # Prev 1.62M event loop iterations/sec (8,085,301 in 5.0s) ~ took 5s ❯ node event-loop.js 72.5K event loop iterations/sec (362,366 in 5.0s) --- const DURATION = 5_000; const origin = performance.now(); let count = 0; function iter() { count++; if (performance.now() - origin < DURATION) { setImmediate(iter); } } iter(); process.once("beforeExit", () => { const elapsed = performance.now() - origin; const rate = count / (elapsed / 1000); let formatted; if (rate >= 1_000_000) formatted = (rate / 1_000_000).toFixed(2) + "M"; else if (rate >= 1_000) formatted = (rate / 1_000).toFixed(1) + "K"; else formatted = String(Math.round(rate)); console.log( `\x1b[1;36m${formatted} event loop iterations/sec\x1b[0m \x1b[2m(${count.toLocaleString()} in ${(elapsed / 1000).toFixed(1)}s)\x1b[0m`, ); });