Evolution of IBM iSeries Performance: A Journey of Continuous Improvement

The IBM iSeries, formerly known as the AS/400, has been an industry leader in the world of midrange computer systems since its inception in 1988. Over the years, IBM has introduced numerous new releases and upgrades, each designed to improve the performance and capabilities of the iSeries platform. This article will explore the key milestones in the evolution of IBM iSeries performance, highlighting the technological advancements that have contributed to its success.

The Early Years: AS/400 and Initial Releases (1988-2000)

The AS/400 was first introduced in 1988 as a successor to the IBM System/38 and System/36. The initial release of the AS/400 featured the 48-bit CISC (Complex Instruction Set Computing) architecture, which allowed for better performance and increased compatibility with existing IBM systems.

Significant performance enhancements in the early years of the iSeries included:

  • The introduction of the RISC (Reduced Instruction Set Computing) architecture in 1995, which increased processing speed and efficiency.
  • The development of the 64-bit architecture in 1998, which allowed for larger addressable memory and improved performance for larger workloads. 

The iSeries Transformation: OS/400 V5R1 (2001)

In 2001, IBM released the OS/400 V5R1, which marked a major turning point in the iSeries’ evolution. This release introduced the IBM eServer iSeries, featuring significant performance improvements, such as:

  • Enhanced memory management, which allowed for better utilization of system resources.
  • Improved I/O performance through the introduction of Fibre Channel technology.
  • The ability to run multiple operating systems simultaneously through logical partitioning (LPAR) technology.  

i5 and POWER5: A New Era of Performance (2004-2006)

In 2004, IBM unveiled the i5 series, which was powered by the POWER5 processor. This release marked a significant leap in performance, with key improvements including:

  • The introduction of simultaneous multithreading (SMT) technology, which allowed each processor core to execute two threads concurrently, resulting in better resource utilization and increased performance.
  • Advanced POWER Virtualization (APV), which allowed for more efficient virtualization and greater flexibility in system configuration.
  • Enhanced performance for Java applications and web services through improved JVM (Java Virtual Machine) optimization.

Continued Performance Improvements: POWER6 and POWER7 (2007-2010)

The iSeries continued to evolve with the release of the POWER6 and POWER7 processors, which brought further performance enhancements, such as:

  • Higher clock speeds, resulting in faster processing capabilities.
  • Enhanced virtualization capabilities with the introduction of the PowerVM hypervisor, which allowed for better resource management and workload consolidation.
  • Improved energy efficiency through the implementation of power-saving features.

The Modern iSeries: POWER8, POWER9, and Beyond (2013-Present)

The iSeries platform has continued to evolve, with the introduction of the POWER8 and POWER9 processors, which have further enhanced performance through:

  • The implementation of high-speed memory interfaces, such as DDR4, which enables faster data access and increased overall system performance.
  • Enhanced support for virtualization and cloud computing through the integration of OpenStack and other open-source technologies.
  • The introduction of hardware-based accelerators, such as the CAPI (Coherent Accelerator Processor Interface), which offloads specific tasks from the processor to improve performance.

V7R5 release in (2022) brings further enhancements and significant performance increases*

  • Boolean search to SQL
  • Power 10 48 core capabilities
  • And many more enhancements

Since its inception, the IBM iSeries has undergone continuous performance enhancements, adapting to the ever-changing needs of the industry. Through the implementation of cutting-edge technologies and innovative features, IBM has consistently raised the bar for midrange systems.

*Recent release of latest OS in past 12 months. IBM provides patches regularly. See performance improvement chart.

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