Why We’re Still Working With Mainframes in 2017

by Steven Melendez ; Updated June 14, 2017

Mainframe – the term sounds like a relic from another era, decades before anyone even heard of smartphones or laptops.

But the appliance-sized computers that helped NASA put men on the moon are actually still widely used at big companies and government agencies – the devices store 80 percent of the world’s corporate data and handle $6 trillion in annual credit card transactions, according to IT company Ensono.

But what exactly are mainframe computers, and why haven’t they been replaced with newer types of machines?

What is a Mainframe?

Mainframes are powerful computer servers designed to handle large numbers of operations on big volumes of data simultaneously. They’re generally the central authority to which other computers connect to execute transactions, like bank transfers, credit card purchases or airline ticket operations. A mainframe released by IBM in 2015 is said to be able to process 2.5 billion transactions a day.

They trace their ancestry back to the System/360, a computer first released by IBM in 1964. It introduced some of the features we take for granted in computers today, like being able to share data across multiple versions of computing hardware, and being able to do multiple types of tasks on the same machine – back then, that generally meant being able to handle both scientific computation and business math on the same type of hardware.

IBM, which makes the vast majority of new mainframes today as part of its "z Systems" line, says the term itself likely comes from the huge metal boxes, some as large in area as a house, that were used to hold the early machines. Now, the computers are a more manageable size – around the scale of a tall refrigerator.

Consistency and Reliability

Mainframe computers are designed to be extremely reliable, not just speedy. They typically have redundant versions of hardware components like disk drives and electrical power supplies, so even if a component fails, the computer can continue to run. They generally also have the ability to add computing power to a given task as needed in essentially real-time, making them well suited to handle spikes in workloads without going down.

At the same time, they’re renowned for what’s called “backward compatibility,” meaning that software created years, or even decades, ago can often still run on today’s mainframes. That’s in contrast to PCs or cellphones, where it can often be impossible to run programs bought for older machines without a lot of specialized work.

That backward compatibility is important for the enormous banks, insurance companies, airlines and other companies that have used the systems since the middle of 20th century. Having to rewrite the computer code that handles the world’s critical transactions in order to run on newer styles of computers would not only be costly, it would also be risky for these large businesses, who will quickly incur bad publicity if the new machines aren’t as reliable as the old. While some businesses have migrated tasks to newer styles of computer hardware and software, many are happy to stick with the ultra-reliable devices. And while mainframe programs may have interfaces that look like they were taken from a 1980s computer hacking movie, but the companies that rely on them know they still work perfectly fine.

Recruiting New Talent

One challenge mainframe-heavy companies can face, though, is hiring engineers and programmers who are familiar with the machines. For at least a decade, computing magazines have reported that techies fresh out of college just aren’t interested in working with the old line of machines. Even in the 1990s, some companies were pull older programmers out of retirement to ensure their mainframe software was ready for the year 2000, when programs designed to store years using two digits rather than four would malfunction.

But mainframe hardware and software companies have responded by offering training and incentives to young people willing to become experts in the machines, as the devices continue to be vital to so much of the economy.

About the Author

Steven Melendez is an independent journalist with a background in technology. He has written for a variety of publications and was awarded the Knight Foundation scholarship to Northwestern University's Medill School of Journalism.