for mysql
activate the cache via the my.cnf
to show the cache "status"
do a SHOW STATUS LIKE ’Qcache%’ ;
the most common queries will be cached
for php
change your "allow_url_fopen" to Off in php.ini, it will avoid some hack where people try to include a remote file as if it was php
note that spip needs a few amount of memory so you won’t need a lot of ressources
http://dev.mysql.com/doc/refman/5.0/en/thread-information.html