Performance: Routing in routes.php vs. Apache mod_rewrite

[eluser]Coomer[/eluser]
Has anyone ever done in-depth investigation into speed differences between routing using Apache's mod_rewrite and using CodeIgniter's routes.php file?

I'm working to make my pages execute extremely fast, and every little bit I can get counts (Even if it's not as easy to add new routes, which is a very uncommon task for me ;-)).

My guess is that using Apache alone and disabling routes in CodeIgniter will yield faster performance (especially since I enable mod_rewrite anyway to remove the index.php from my URLs), but I was curious as to if anyone had any definitive answers here. I searched but didn't find a whole lot about routing performance.