Even for small scale stuff, the "default" nginx way of using PHP is much better - with php running in its own process via php-fpm or fastcgi. If you are running Apache with PHP-FPM you can get similar performance, but you find fewer how-tos and documentation on that since most Apache users leave modphp in place.
With modphp in limited memory environments you run into memory swap issues super fast unless you are careful about your Apache configs, since it will, in most default environments, spawn many more Apache processes than you have memory for. PHP makes the Apache process use 20-200M of memory for many standard apps like drupal or wordpress. Put it on a 1Gig linode without turning down the MaxClients and add 10 concurrent users and you will see the site grind to a halt. Now install nginx and php-fpm and follow anyone's basic how-to, it will only spawn as many php processes as your memory and cpu cores can handle, and nginx will keep spinning out the static files while php is churning in the background, living within reasonable memory bounds.
You can achieve the same thing in Apache, but I never really knew how to do that until Nginx taught me. I have never seen Apache set up right for this in any of my clients' existing servers and they can never scale at all.
Modphp is a bit faster if you have enough memory for your PHP application * the number of simultaneous connections, but that is hardly ever the case, since Apache will be reusing the same high memory processes for every jpg and css file that it does for all of the php requests and 2-3 simultaneous users can make 20-30 concurrent requests. You better make sure that your maxclients is set to your physical memory divided by your php app's memory use. In a 1G VPS this might be 1024M/64M = 16. Save some memory for MySQL if it is on the same server and you probably shouldn't have MaxClients over 10. Now all of the css, jpg and png files are waiting in-line for the 500ms php scripts to finish and the site loads slow. Many PHP apps eat up over 128M per process, even though a typical request is smaller, that one crazy request eventually bloats all of the processes and you are swapping. If PHP starts hitting swap, your request times are rising up to 3-5 seconds real quick.
I had a small VPS with apache and modphp that could only handle about 20 concurrent requests because it'd hit the memory limit so fast. I switched to nginx and php-fpm and it could then easily handle 5x the concurrent requests in the same memory footprint.
With modphp in limited memory environments you run into memory swap issues super fast unless you are careful about your Apache configs, since it will, in most default environments, spawn many more Apache processes than you have memory for. PHP makes the Apache process use 20-200M of memory for many standard apps like drupal or wordpress. Put it on a 1Gig linode without turning down the MaxClients and add 10 concurrent users and you will see the site grind to a halt. Now install nginx and php-fpm and follow anyone's basic how-to, it will only spawn as many php processes as your memory and cpu cores can handle, and nginx will keep spinning out the static files while php is churning in the background, living within reasonable memory bounds.
You can achieve the same thing in Apache, but I never really knew how to do that until Nginx taught me. I have never seen Apache set up right for this in any of my clients' existing servers and they can never scale at all.
Modphp is a bit faster if you have enough memory for your PHP application * the number of simultaneous connections, but that is hardly ever the case, since Apache will be reusing the same high memory processes for every jpg and css file that it does for all of the php requests and 2-3 simultaneous users can make 20-30 concurrent requests. You better make sure that your maxclients is set to your physical memory divided by your php app's memory use. In a 1G VPS this might be 1024M/64M = 16. Save some memory for MySQL if it is on the same server and you probably shouldn't have MaxClients over 10. Now all of the css, jpg and png files are waiting in-line for the 500ms php scripts to finish and the site loads slow. Many PHP apps eat up over 128M per process, even though a typical request is smaller, that one crazy request eventually bloats all of the processes and you are swapping. If PHP starts hitting swap, your request times are rising up to 3-5 seconds real quick.