Here is a callgrind for a simple application in PHPixie that accepts a url parameter, uses ORM to access the object from the database and renders a view. What it displays is the time that was used on each function call, the bigger the block the longer it was executing. Nested blocks depict functions being called inside other functions.

PHPixie PHP framework call map

It would seem that autoloading and getting configuration parameters take up most of the time, which is true because both require searching the filesystem. Let’s now compare this to something more tangible, e.g. a 0.01s delay.

PHPixie PHP framework callgrind compared to 0.01s delay

The picture is much clearer now, that small delay took 57% of the call time compared to PHPixie, so even if you are really concerned about the speed of your application you don’t need to worry at all about PHPixie being any kind of overhead.