PHP 5.4 is Not twice as fast as 5.3

For some real-world(ish) benchmarks, see : http://news.php.net/php.internals/57760

Memory usage is the big winner, e.g. a 50% improvement for Drupal, with performance in terms of requests per second being lower (e.g. 7% for Drupal) but still an improvement. And memory improvements can lead to greater performance improvements when scaling out or on overloaded hardware.

Just to note, this was back in February in a pre-release version of 5.4, and things have improved in a couple of areas since then.

I recently did some testing of PHP 5.4 and found pretty much the same thing. Its faster but not _that_ much faster.creating and serializing a huge object to YAML still take about the same time. The only thing I have found is that I get a little bit better performance out of mod_php, and memory usage is down about 20%