Which leaves the question: are you sure that your application is written such that it does not serialize requests internally? If you have synchronisation bottlenecks you can start as many threads as you like, but only a few may actually be runnable. You can check samples of the state of your threads using jconsole. If you find that most of them are waiting, blocked on a lock of some kinds it makes no difference how many processors you have. So, what makes you so sure that all threads in your application are free to run? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4171807#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...