The fixed cost of installing a PHP framework: disk size tells you nothing
How many megabytes on disk, how many files per request and how many milliseconds on the first request do seven PHP frameworks cost — and which of those numbers actually predicts throughput under load?
Finding
Disk size predicts nothing: Yii2 has the largest vendor tree at 34.1 MB and loads only 62 files per request, among the fewest in the field. Files per request predicts nothing either: CodeIgniter loads 96 files and serves 6,431 req/s, Symfony loads 224 and serves 13,067. The one number that genuinely separates them is the first request served with a cold opcache: 2.2 ms for Phalcon, 72.2 ms for Laravel — thirty-three times. That is the compile bill the first visitor pays after every deploy, and it is measured in tens of milliseconds, not kilobytes.