Memory usage of fresh nginx

[Ensiferous]

The difference in the Nginx memory size can be due to the modules you
have compiled in or the amount and size of buffers you have allocated.

The difference in the PHP memory size can be anything from modules
compiled in/dynamically linked to what type of scripts you're running.

One thing I can tell you with certainty is that Nginx does not affect
the memory usage of PHP.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,207506,207750#msg-207750