Is there some OS config setting that is preventing JBoss AS from using all procs? I have a quad-core desktop on on both Vista and Ubuntu I can get JBoss AS to use all four cores. Also, how are you determining that JBoss AS is using one one processor? The startup tends to be single-threaded because of the way deployment is done. But HTTP access in multi-threaded to under load you should see a lot of multi-processor usage. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4214363#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...