Home history IBM zSystem IBM zSystem
The world’s most powerful mainframes continue to push technological boundaries while powering global finance and online commerce
Close-up of the upper right side of the IBM System z mainframe, showing a blue horizontal stripe above the IBM logo.

When e-business exploded in the late 1990s, it created a disconnect between the capabilities of existing data center technologies and the internet aspirations of countless companies around the world. Suddenly, sales channels were always open, relentlessly demanding, global and dynamic — and the technology of the day couldn’t keep up. In 2000, IBM unveiled the eServer zSeries 900, built with e-business as its primary function, to close that gap.

The Z series (Z stands for “zero downtime”) introduced several breakthroughs that continue to be employed today. For the first time, it enabled thousands of servers collaborating within a single physical rack — or frame — to handle unpredictable traffic spikes, which had become an especially thorny challenge. And it introduced a set of components to enable so-called hot failovers, whereby traffic could be redirected to standby computers to ensure continuous operations.

The 64-bit zOS, which remains in use, featured world-class security and was backward-compatible with the IBM System/360 and System/370, which had been introduced decades earlier. Additionally, IBM introduced a novel pricing arrangement based on actual demand rather than total capacity.

The zSeries 900 was an immediate hit, especially in the financial sector, where data security is paramount and even a minute of downtime can cause USD 1 million in losses. It also kicked off a long line of increasingly more advanced systems that have evolved to support open-source platforms, cloud computing and AI. More than two-thirds of the Fortune 100 continue to use the IBM zSystems family to manage mission-critical operations and to protect their most sensitive data.

More than two-thirds of the Fortune 100 continue to use the IBM zSystems family
The evolution of the mainframe
Faster, greener and more secure

IBM spent two years and USD 1 billion developing the zSeries 900, and over the ensuing years relentlessly worked to increase clock speeds, harden security, and increase system efficiency to reduce environmental impact.

In 2003, the zSeries 990 debuted with sufficient capability to handle 9 billion instructions per second on 32 processors — roughly three times as fast as the zSeries 900. In 2010, the IBM zEnterprise System emerged with the fastest processor cores in the industry, running at 5.2 gigahertz. It housed 96 cores on a single machine and 3 terabytes of main memory. In addition to helping IT departments integrate heterogeneous workloads, the new generation required significantly less power and space than its predecessors.

Five years later, IBM released the IBM z13. The culmination of another USD 1 billion investment in development and collaboration with more than 60 enterprise clients, it featured real-time encryption to battle the persistent threat of increasingly sophisticated hackers. The z13 development team yielded more than 500 patents. IBM z14 marked a significant advance in data privacy and security by introducing pervasive encryption. It simplified encryption of data everywhere, at rest and in motion, and reduced costs associated with protecting data while achieving compliance mandates. IBM harnessed that same confidential computing capability for Hyper Protect Services through the IBM Cloud, providing clients consistent protection of their mission-critical applications and data whether on premises or in the cloud.

zSeries 990 capabilities 32 processors 9 billion instructions handled per second 5.2 gigahertz speed 96 cores on a single machine
IBM z15
A raft of new features

The IBM z15 followed in 2019, running on the IBM System/390 chip architecture. Its notable innovations include the abilities to work with immense caches and to support several Linux operating systems and a plethora of open-source applications. IBM clients commonly run multiple operating systems on a single IBM z15.

The development team garnered 3,000 patents and introduced numerous innovations to further enhance business value. Data privacy passports, for example, granted clients control over the storage and sharing of sensitive data and enabled administrators to revoke access at any time across an enterprise’s entire hybrid multicloud environment. Cloud-native development — allowing the construction and operation of responsive and scalable apps in modern, dynamic environments such as public, private and hybrid clouds — gives clients a new way to expand and securely connect to clouds with open-source development tools.

The IBM z15 was also designed to advance sustainability in the data center. It reduced overall system power consumption by 50% over previous versions and required 75% less floor space. Clients who upgraded from z13 and z14 saved an estimated 62 million kilowatt-hours per year and emitted 43,904 fewer metric tons of CO2.

On-chip AI acceleration

IBM zSystem continues to flourish to this day, growing faster, more flexible, greener, more secure and more indispensable with each new release. Incorporating Design Thinking into each platform delivers additional innovations and greater value and relevance to global business. Of the world’s top 50 banks, nearly all rely on IBM zSystem. The same holds true for the top 10 insurance companies and countless clients across government, healthcare and the airline industry.

In August 2021, IBM unveiled the IBM Telum Processor, the next-generation chip designed with technology from IBM Research. It leverages deep-learning inference to help address fraud and other new use cases in real time and at scale. It’s the first IBM processor with on-chip acceleration for AI network training during a transaction. Three years in development, Telum was designed to help clients achieve business insights with IBM z16 across banking, finance, trading, insurance applications and customer interactions. The IBM z16 system also includes quantum-safe cryptography to protect today’s systems and client data from tomorrow’s technologies.

IBM is currently developing the next two generations of zSystems to ensure the continued delivery of breakthrough technologies and world-class experiences that the company’s clients have come to expect. The mainframe revolution, in otherwords, is very much alive.

Related stories Breaking the petaflop barrier

IBM Roadrunner smashed an elusive speed record and marked a new era in supercomputing

The IBM System/390

In 1990, IBM debuted a mainframe for an internet world

Data security and privacy

IBM has been a leader in protecting data security and privacy since the dawn of computers