PHP-FPM vs RoadRunner vs Swoole: Docker vs Bare Metal Performance (2026)
After our deep dive into PHP 8.5 JIT modes and the bare metal application server benchmarks, many readers asked the same question: Does Docker really slow down PHP application servers? Today we benchmark PHP-FPM, RoadRunner, and Swoole in three scenarios: bare metal, Docker default bridge network, and Docker host network + CPU pinning. The results are surprising—with the right flags, Docker can actually outperform bare metal.