There are now three major MPMs: Prefork - if you want to use mod_php, you're stuck with this. I think this is what you're referring to as "the process model"

There are now three major MPMs: Prefork - if you want to use mod_php, you're stuck with this. I think this is what you're referring to as "the process model" Worker - Uses threads to handle connections. A big step up from prefork, but not as awesomesauce as nginx. Evented - The new MPM which use epoll It's been possible to run PHP(-fpm) under "worker" (via FastCGI) for years, and it performs adequately. I never benchmarked, but I was using this setup back when nginx was still too bleeding-edge for my tastes, and it certainly beat the pants of prefork/mod_php