I use wordpress on Ubuntu 12.04 with Nginx + php-fpm on my VPS. There are 2 CPU cores + 4096Mb memory.
I've moved mysql database to another server and set remote access. There are about 300 online visitors at once and php-fpm uses really a lot of CPU:
I also use APC-cache and batcache for wordpress.
php-fpm config:
listen = /var/run/fpm-macradar.sock
;listen.backlog = -1
pm = ondemand
pm.max_children = 30
pm.start_servers = 15
pm.min_spare_servers = 10
pm.max_spare_servers = 20
;pm.process_idle_timeout = 10s;
pm.max_requests = 500
pm.status_path = /status
chdir = /
request_slowlog_timeout = 60s
slowlog = /var/log/$pool.log.slow
request_terminate_timeout = 120s
rlimit_files = 131072
rlimit_core = unlimited
catch_workers_output = yes
;php_flag[display_errors] = off
php_admin_value[error_log] = /var/log/fpm-php.www.log
php_admin_flag[log_errors] = on
php_admin_value[memory_limit] = 128M
Any help will be appreciated