Speeding up PHP means removing repeated work (compiling the same files, rebuilding the same data), holding less memory per worker, and running the right number of workers for the traffic: OPcache, then memory habits and data caches, then the PHP-FPM pool.
Every number here was measured on one machine, an Ubuntu 26.04 225 WSL2 6 guest with 36 logical CPUs and 64 GB of RAM, running PHP 8.5.4 under PHP-FPM behind Apache 2.4.66 129 with the event MPM and proxy_fcgi (PHP-FPM via proxy_fcgi). The realistic workload is the welcome page of a fresh Laravel 13 2,157 skeleton (Laravel): 496 PHP files per request, with sessions in memory. Your absolute figures will differ; the ratios carry over.