This question is often asked, but is never answered properly. So how to measure framework speed? Let me also explain why "scalability" is more important than general "performance". [...] This along with a general overheads of the framework greatly contributes to the "slowness" of your project. So how can framework contribute to performance of your project?

They touch a few different ways that frameworks can help execute things a bit faster like:

• Make Fewer SQL Queries
• Selective render
• Parallelization
• Overheads
• Caching

Hierarchical-MVC has been shown to make large web applications easier to scale out, but there is a price to pay- namely overall performance. This article will investigate ways of improving performance within HMVC web applications using asynchronous processing and some good old caching techniques. Predominantly this article will use examples written for the Kohana Framework; however all the concepts portrayed here could apply to any framework or web application.

He starts by pointing out what's wrong with the typical HMVC application - namely that the clean separation of code structure (the hierarchical part) costs the application in overall speed and memory usage. He suggests a simple technology for helping ease the load - caching as much information as possible, mostly in the HTTP client code since HMVC applications rely heavily on it. Code samples includd show how to implement this in a simple Kohana application.

The advantages of this include full test isolation and the fact that a test can now cause a PHP fatal error or even a segmentation fault of the PHP interpreter without interrupting the test execution.

He does mention, however, that it can cause a bit more overhead for larger testing suites since it needs to create a new process (complete with memory usage) for each running test. There are also coding issues that could be thrown off by this option (he gives an example of an inheritance issue with eZ Components).

He also notes some of his thoughts on how to control/configure the process (like in a configuration file) and via an "@isolated" notation to make it easy to do it dynamically.

He asks the question: "Is there significant overhead to the is_ functions like is_array, is_object, is_string in php?" He wonders if those kinds of functions, since they are on such a base level, could cause more trouble than their worth when used en masse. He asks because it's used heavily in an approach for his developing Ookles application.

There's already been one comment made on the post, and it mentions that they are, in fact, a trivial call to PHP. It's a simple test that validates simply without much need for too much background action. It does mentions some caveats - is_object, is_resource, and, at times, is_callable.