This article provides performance tuning approaches, guidelines and tips for IBM WebSphere DataPower SOA Appliance, since performance is a key attribute for WebSphere DataPower it is very important to be able to tune the device to achieve expected performance results.
http://www.ibm.com/developerworks/webservices/library/ws-dpperformance/index.html?ca=drs-
Thys Michels Blog 