Is there any possible reason why the multi-thread ParallelOldGC is running poor than the single thread one? View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4239582#4239582 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=4239582