Thanks 4 the explaination so from those 3 which is the best one in a memory intensive web app ? (outofmemeory heap error often happen in development and testing in 32bit with less than 10 concurrent users, and when in production mode it must be able to handle 100-300 concurrent users) on a x86_64 multi-processor server with 32 giga of fb RAM View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4205650#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...