The Symfony Finland blog site has worked up some benchmarks comparing the Symfony Proxy versus Varnish and shared the results in this new post. The Symfony Proxy is a tool built in to the framework to help with caching responses automatically. Varnish, however, is a separate tool optimized to handle the caching of the same content but outside of the application completely.
In the previous articles we have evaluated PHP performance on different runtimes (PHP 5.6, HHVM, PHP 7) as well as how it behaves when adding server resources (CPU & RAM) using eZ Platform - a CMS built on the Symfony Framework.
In production environments Symfony and eZ Platform are likely ran behind the Varnish Reverse Proxy, which we'll evaluate next by comparing it to the built in Symfony Proxy.
They once again use the eZ platform demo application as the software under test on an 8 Core machine. The results aren't overly surprising if you're familiar with Varnish at all. Software-based caching layers are helpful but when you are able to remove the processing overhead of it from an application, you're better off.