PHP performance

Question

What can I do to increase the performance/speed of my PHP scripts without installing software on my servers?

Answer 1

One reasonable technique that can easily be pulled off the shelf is caching. A vast amount of time tends to go into generating resources for clients that are common between requests (and even across clients); eliminating this runtime work can lead to dramatic speed increases. You can dump the generated resource (or resource fragment) into a file outside the web tree, and then read it back in when needed. Obviously, some profiling will be needed to ensure this is actually faster than regeneration - forcing the web server back to disk regularly can be detrimental, so the resource really does need to have heavy reuse.

You might also be surprised how much time is spent inside badly written database queries; time common generated queries and see if they can be rewritten. The amount of time spent executing actual PHP code is generally pretty limited, unless you're using some sub-optimal algorithms.

Neither of these are limited to PHP, though some of the PHP "magicy" approaches/functions can over-protect one from thinking about these concerns. For example, I recently updated a script that was using array_search to use a binary search over a sorted array, and gained the expected exponential speedup.