At the moment, I can only get good perfSender/perfListener results if I change producer and consumer-window-size to something smaller on the ConnectionFactory. from jbm-jndi.xml: <connection-factory name="ConnectionFactory"> | <entry name="ConnectionFactory"/> | <entry name="/ConnectionFactory"/> | <entry name="/XAConnectionFactory"/> | <entry name="java:/ConnectionFactory"/> | <entry name="java:/XAConnectionFactory"/> | <producer-window-size>90000</producer-window-size> | <consumer-window-size>90000</consumer-window-size> | </connection-factory> | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4167350#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...