Advanced features in IBM POWER8 systems

The IBM POWER8™ processor includes many innovative features that enable efficient and flexible computing, along with enhancements in virtualization, security, and serviceability. These features benefit application performance, and big data and analytics computing, as well as the cloud environment. Notable features include the capabilities to dynamically and efficiently change the number of threads active on a processor, enhancing application performance via integer vector operations, encryption accelerations, and reference history arrays. Also notable is improved virtual machine density (supporting multiple simultaneous partitions per core and providing fine-grain power management), allowing continuous monitoring of system performance as well as significantly enhanced system RAS (reliability, availability, and serviceability) and security. Each of these features is technologically complex and advanced. This paper provides an in-depth description of some of these features and their exploitation through systems software and middleware. These features will continue to bring value to the system-of-record workloads in the enterprise. They also make POWER8 systems well-suited for serving the needs of newer workloads such as big data and analytics, while efficiently supporting deployment in cloud environments.

I. Introduction

Over the years, IBM POWER**Trademark, service mark, or registered trademark of International Business Machines Corporation in the United States, other countries, or both. processors [1]– [5] have delivered many innovations to the marketplace, including the RISC (reduced instruction set computing) architecture, advanced branch prediction, out-of-order execution, data prefetching, simultaneous multi-threading, dual-core chips, core accelerators [5], on-chip high-bandwidth memory-controllers, and highly scalable SMP (symmetric multiprocessor) interconnects. In this eighth-generation POWER processor [6] [7], IBM continues the tradition of innovation by introducing a balanced, 12-core multi-chip design, with large on-chip eDRAM (embedded dynamic random access memory) caches and high-performance eight-way multithreaded cores.