that helps reduce latency, but if you can't accept new connections, it's of no use.

Also note that initcwnd is set to 10 by default on all current OSen.

CentOS is used on a great percentage of webservers and it does not set initcwnd to 10 by default.

Sadly we have to wait even longer for initrwnd support (minimum 2.6.38 kernel)

elrepo has up to date kernels for centos.