Optimizing PHP for speed
By Mukesh Tandi · Performance
PHP is fast enough for almost any site — if you configure it properly. Most "slow WordPress" problems aren't PHP's fault; they're missing caches and lazy defaults. Here's what actually moves the needle.
1. Turn on and tune OPcache
OPcache stores compiled PHP in memory so it isn't re-parsed on every request. Give it enough memory (128–256MB), raise max_accelerated_files, and on production set validate_timestamps=0 so it doesn't stat files constantly.
2. Use a persistent object cache
Redis or Memcached lets WordPress reuse expensive query results across requests. On a busy site this alone can cut database load dramatically and drop response times.
3. Cache full pages where you can
For anonymous visitors, serve a cached HTML page instead of booting PHP at all. LiteSpeed Cache or a reverse proxy handles this and keeps TTFB low under load.
4. Use a modern PHP version
Each recent PHP release is measurably faster than the last. Staying current is one of the easiest free speed upgrades you can make.