What is occupied by my RAM on the server?

Question

linux

when loading a category, loads the processor up to 80%
site
linking nginx + apache + php + mysql
to php - apc, fastcgi, deflate
pictures loads from amazon s3
in the cache constantly 800 meters of op memory. busy

Answer 1

Your RAM was occupied by the Apache tribe. In Apache, in the config, reduce the number of worker processes.

Answer 2

mysql, apache.
make fewer processes in apache, in mysql go through mysqltuner.pl, see what he advises to reduce.