The IBM Power4

In the mid-1990s, IBM was facing an unfamiliar problem. The company had built its reputation on producing a long line of incredibly powerful computers, from machines like the 7030 Stretch, which reigned as the world’s fastest in the early 1960s, to RISC-based machines and the IBM PC. But by 1996, IBM ranked fifth out of five companies in the burgeoning Unix server market — primarily due to the speed of its microprocessors. The exploding popularity of the internet significantly increased the demand for faster servers, and IBM was caught flat-footed. Incremental improvements wouldn’t solve the issue. An entirely new approach to processor architecture was in order.

So, a handpicked team of 250 systems and chip designers, software architects, researchers and semiconductor engineers set out to reinvent the microprocessor and much of its supporting architecture. In the arcane world of CPU design, IBM engineers and scientists had to break new ground in pipelining — the process of accumulating instruction from the processor in an orderly fashion, which keeps all portions of the processor occupied and increases the amount of useful work the processor can do at a given time. Engineering advances were also necessary in multithreading, a CPU feature that enables two or more instruction threads to execute independently while sharing the same resources. This allows multiple concurrent tasks to be performed within a single process. The hope was to leapfrog competitors with a wholly new server system that would offer twice the performance at half the cost.

The project took nearly five years to complete, but the result was a game changer. The team successfully grafted two high-performance microprocessor cores on a single silicon chip — an industry first — and developed a novel computer architecture to support it. The dual-core processor enabled multiple programs to run simultaneously, or a single program to run faster and more efficiently. Dubbed IBM Power4 (POWER was originally an acronym for “Performance Optimization With Enhanced RISC”), the new processor served as the brains for an IBM eServer pSeries server called IBM Regatta. It met the goal of more than doubling the speed of the nearest competitor at half the cost. Microprocessor research company Cahners In-Stat/MDR awarded the Power4-based system its Analysts’ Choice Award for Best Workstation/Server Processor of 2001.

In October 2001, IBM launched what was then the world’s fastest server, code-named Regatta, around Power4. The breakthrough processor design enabled Regatta to conserve energy and dramatically outperform servers with twice as many processors. Power4 was an instant hit with customers and reviewers, and vaulted IBM back into the lead of the Unix server segment. “Everything about IBM’s Power4 processor is amazing,” gushed a review in PC Magazine. “Amazing technology, amazing size (680 million transistors), amazing power requirements, amazing performance.”

The new system-level architecture spawned an entire Power series, which became the heart of IBM’s line of industry-leading servers for decades to come. In 2005, more than a dozen companies, including Sony and IBM, formed Power.org, an open-standards community focused on accelerating Power chip collaboration. Power microprocessors became the core of everything from game consoles to powerful supercomputers. Watson, the computer that defeated human opponents on the TV quiz show Jeopardy!, was built on Power7 technology.

In 2021, IBM introduced the Power10 processor, designed specifically for hybrid cloud environments. It’s the heart of the IBM Power E1080 server, which can deliver up to 30% more performance per core, while consuming 33% less energy, compared with the previous generation of IBM servers — enabling customers to consolidate workloads and save on hardware and software costs.

The continuously high level of microprocessor performance is further proof that IBM’s breakthrough design in the late 1990s has had staying ... power.