On the Forma-Pro.com blog there's a new post from Maskim (their Chief Architect) comparing PHP AMPQ libraries including some benchmarks of their performance of their handling of messages.

Increasing popularity of AMQP interop prompted a wave of questions regarding which adapter is the fastest. In this post, I am going to share my findings of message publishing performance. There will be a similar post about consumption side.

He compares three of the main libraries: php-amqplib, amqp-ext and bunny (as well as their adapters for interoperability). To get a good comparison he's also thrown in one written in Golang for external comparison. He start be outlining the system specs he used for testing and then various graphs of the benchmark results. The results of his benchmark script are interesting with only a few oddities here and there. The post finishes with a summation of the results but you'll have to head over there to see those results.