A 2026 benchmark compared PHP 8.5, Node.js 22, Go 1.24, and Python 3.12 under database I/O load, finding that PHP 8.5 with Swoole coroutines achieved 4.9–5× higher throughput than traditional synchronous runtimes at 50–200ms latency. Swoole's coroutine-based concurrency model allowed single workers to handle multiple concurrent requests, dramatically outperforming PHP-FPM, Node.js, Go, and Python in I/O-bound scenarios.
A developer benchmarked HTTP server performance by building identical routes in C++ (using Crow and uWebSockets libraries) and Node.js. Node.js initially outperformed Crow due to async I/O differences, but uWebSockets achieved 57k req/sec compared to Node's 12k, demonstrating that library choice and I/O model matter more than language alone.
epoll and kqueue are kernel APIs that enable efficient I/O multiplexing by registering interest in file descriptors once rather than repeatedly polling them, making high-concurrency servers feasible by reducing CPU overhead from O(n) scanning to O(activity).