Mainframe turns 60 with no plans for retirement

On April 7, 1964, International Business Machines introduced a new computer dubbed the System/360 but called a “mainframe” in reference to the large cabinet that housed the circuit boards. The low-end model, the Model 30, came with 8 KB to 64 KB of memory, while higher-end models could have up to 8 MB of main memory.

From that came a technology platform that has survived six decades and numerous predictions of its demise. In 2024, as it reaches 60 years old, the mainframe is still enjoying significant use. According to IBM:

• Mainframes are used by 71% of Fortune 500 companies.
• Mainframes handle 90% of all credit card transactions.
• Mainframes are used in 44 of the top 50 banks.
• Mainframes handle 68% of the world’s production IT workloads, yet they account for only 6% of IT costs.

Forrester Research in its State Of Mainframes, Global, 2024 report said, “Contrary to the claim that mainframes are slowly disappearing, 54% of respondents whose enterprises currently use a mainframe expect to increase their mainframe use over the next two years with 27% reporting no change, while only 15% expect decreased usage.”

“The mistake most people make concerning mainframes is to assume it’s all about computing,” said Charles King, principal analyst with Pund-IT. “Sure, you can successfully argue about the value of various IBM Z mainframe compute elements. But the continuing success of mainframe solutions really depends on two things: one, IBM’s deep understanding of enterprise customers’ business needs, and two, the Z platform’s remarkable adaptability. Put those two things together, and you have a solution capable of evolving to meet virtually any enterprise requirement.”

The Z platform’s adaptability was on display in 1999, when IBM said it would support Linux on the mainframe, an acknowledgement of the open-source software’s growing influence. The significance of this move cannot be overstated. Linux had been on the market for a decade at this point and was primarily used on x86 PCs. Now it was running on a mainframe, the epitome of performance and reliability. It was a very bold move. (Read about many more of IBM’s game-changing mainframe moments)

Today, IBM continues to modernize the platform – last year it delivered an AI-infused version of its z/OS operating system; it reported double-digit growth in its big iron business for the quarter ended September 2023; and it launched a mainframe training program to build up a skilled, sustainable workforce for the mainframe.

“After an initial period of migration off the mainframe in the early 2000s of workloads that didn’t require mainframe capabilities, the platform has stabilized around a customer base of thousands of organizations that not just continue to run their most critical workloads on the mainframe, but they are indeed modernizing those workloads,” said Peter Rutten, research vice president for performance intensive computing at IDC.

Every release of a new generation mainframe comes with a slew of innovations that enable the platform to provide unmatched online transaction processing with the highest possible availability, while at the same time delivering innovative – sometimes industry-first – solutions, such as pervasive encryption across the platform, hybrid cloud, and AI inferencing functionality built into the processor, Rutten added.

“The mainframe doesn’t die – it just morphs,” he said.