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).
Table of contents
Chapter 1. Optimization and tuning on IBM POWER8
Chapter 2. The POWER8 processor
Chapter 3. The POWER Hypervisor
Chapter 4. AIX
Chapter 5. IBM i
Chapter 6. Linux
Chapter 7. Compilers and optimization tools for C, C++, and Fortran
Chapter 8. Java
Chapter 9. DB2
Chapter 10. WebSphere Application Server
Appendix A. Analyzing malloc usage under AIX
Appendix B. Performance tooling and empirical performance analysis
These pages are Web versions of IBM Redbooks- and Redpapers-in-progress. They are published here for those who need the information now and may contain spelling, layout and grammatical errors.
This material has not been submitted to any formal IBM test and is published AS IS. It has not been the subject of rigorous review. Your feedback is welcomed to improve the usefulness of the material to others.
IBM assumes no responsibility for its accuracy or completeness. The use of this information or the implementation of any of these techniques is a customer responsibility and depends upon the customer's ability to evaluate and integrate them into the customer's operational environment.