Obtaining the very best performance from a network adapter is not always a simple task. IBM adapters and their device drivers undergo extensive performance analysis in order to derive the best default configuration for the majority of possible configurations in which they are going to be placed. However, each environment introduces specific characteristics that affect the ability of the adapters and device driver to achieve the highest performance. IBM adapters and their device drivers are engineered to allow the user a great amount of flexibility to tune the performance in their specific environment. This includes not only many performance-based configuration parameters but also enhanced functions whose sole purpose is to achieve the highest performance possible, such as Route Switching and Class of Service for IP.
Tuning network adapters for the very highest performance is such a large topic that it is best addressed in a separate document. The following URL will take you to an IBM white paper explaining steps to achieve the best performance from your IBM adapters for your specific networking environment:
http://www.ibm.com/networking/per/per10.html