Would this work for IPB?

http://www.igvita.com/2008/02/11/nginx-and-memcached-a-400-boost/

IP.Board will work with nginx php-fpm and memcache.

That's really not necessary. Nginx has it's own caching module. If you want the caches to be on ram, just point nginx's cache location to ramdisk.

memcached is used for caching some calls from php to mysql.

I had realized a huge reduction on db processes runing after enabling memcache

We already have Xcache enable. We already run nginx. My question was about enabling memcache for nginx.

I do not have it connected with nginx, it's just enabled and correct flag set up in IPB-config and ammount of calls to db is reduced.

Will try to enable it in nginx