I hear what you're saying, but I'm having trouble arguing with the results I've seen :-)

Indeed, my test case was trivial -- it launched, performed the application initialization, did some trivial tasks, and quit.

I was testing this with OpenPlugin, which internally makes use of Class::Factory. So, when OpenPlugin starts up, it calls Class::Factory's add_factory_type for each plugin (in my test case, that included 7 plugins). Each plugin then loads it's driver, and each driver in turn loads it's dependencies. So off the top of my head, let's say add_factory_type ends up loading roughly 20 modules.

And this is where I'm saying I saw the performance difference. I did not benchmark this per se, I profiled it. Using Devel::Profile, I realized that my app was spending quite a bit of time in add_factory_type, where it would be loading all these modules.

I ran that several times, and found the results to be consistent -- each call to add_factory_method was taking about 0.010652 seconds per call. Changing the code within add_factory_type to use "use" instead of "require" lowered the execution time of that method to about 0.000904 seconds per call, and lowered the overall execution time of the application.

If I change it back to "require", the execution time for the entire app goes back up.

Could there be something with OpenPlugin, perhaps the amount of modules it ends up loading, or maybe even something in one of the modules that it's loading, that has it showing different results than what one might expect?

Thanks for your thoughts. Have a good one,