I do bunch of portal perf and scalability test on 64bit machine with 64-bit sun jvm and I have not have any problem. But that's not your answer, is it? :-) You need to increase perm gen size. In your JVM options. change your run.conf as: | JAVA_OPTS="-Xms512m -Xmx512m -XX:NewRatio=10 -XX:PermSize=64M -XX:MaxPermSize | =128M -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=36 | 00000" | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4129482#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...