This option is very important. Cpnginx doesn’t install the google pagespeed module by default. To enable this module you may follow the given procedure.
1) Enable google pagespeed from WHM → Cpnginx → Settings
2) Compile nginx as follows
# nginxctl nginxbuild --enable-pagespeed
This will enable google page speed module.
If google pagespeed enabled, cpnginx will automatically add a cdn domain for every virtual host. It may start with the keyword cpnginxcdn . For example if you have a domain name mydomain.com , then the cdn domain name will be cpnginxcdn.mydomain.com. So that you can use an external cdn service to boost the google page speed for static contents.