This IBM® Redbooks® publication focuses on gathering the correct technical information, and laying out simple guidance for optimizing code performance on IBM POWER8™ systems that run the AIX®, IBM i, or Linux operating systems. There is much straightforward performance optimization that can be performed with a minimum of effort and without extensive previous experience or in-depth knowledge. The POWER8 processor contains many new and important performance features, such as support for eight hardware threads in each core and support for transactional memory. POWER8 is a strict superset of IBM POWER7+™, and so all of the performance features of POWER7+, such as multiple page sizes, also appear in POWER8. Much of the technical information and guidance for optimizing performance on POWER8 presented in this guide also applies to POWER7+ and earlier processors, except where the guide explicitly indicates that a feature is new in POWER8. This guide strives to focus on optimizations that tend to be positive across a broad set of IBM POWER® processor chips and systems. Specific guidance is given for the POWER8 processor; however, the general guidance is applicable to the IBM POWER7+, IBM POWER7®, IBM POWER6®, IBM POWER5, and even to earlier processors. This guide is directed to personnel who are responsible for performing migration and implementation activities on IBM POWER8-based servers. This includes system administrators, system architects, network administrators, information architects, and database administrators (DBAs).
