Joel Drapper's clarification of a widely cited benchmark: Phlex actually does more work than ERB to render a single HTML tag, so claims like 'Phlex is 12× faster than ERB' (still on the Ruby UI website) are misleading. Where Phlex wins decisively is on pages with thousands of partials/components — because ActionView has to find and compile each partial file, its overhead grows quickly, while Phlex's per-component overhead stays tiny. On a modern machine (M4, single core) Phlex rendering will saturate a network connection before the CPU, so the performance question is usually moot.