depending on your setup you might think about serving static
content and videos directly from nginx:
http://www.nginxtips.com/optimizing-nginx-for-video-sites/

anything served directly from nginx, not going to apache will boost your
performance.


> Mex, That's a high amount of reduction in load-avg than :). Could you
> please refer me to some guide to start with nginx-cache ?

http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_cache
http://wiki.nginx.org/ReverseProxyCachingExample

a little more detailed:
http://reviewsignal.com/blog/2013/08/29/reverse-proxy-and-cache-server-with-nginx/





> And also it's
> drawbacks if i put the wrong configs ?

stale content, but it might be ok to run with a very short cache-time