Web Application very slow in TOMCAT

[Sarandy]

We have implemented an application to start the Tomcat service works very quickly, but spending hours and when more users are entering is getting slow (up to 15 users approx.).

Checking RAM usage statistics (20%), CPU (25%)

Features of the machine:
8GB RAM
i7 PROCESSOR
Windows Server 2008 64bit
Tomcat 7
MySql 5.0
Struts2
We do not use Web server, we published directly on Tomcat.
*** -Xms1024m
**** PermGen = 1024
**** MaxPernGen = 1024