Description of a Mainframe Computer

Updated April 17, 2017

Mainframe computers are in a league all their own and despite reports and speculation that they are history, new mainframe computer models are still being developed and introduced. As recently as 2010 IBM announced the zEnterprise machine, putting to rest for now the rumours of the mainframe's demise. These computing monoliths provide security, availability and reliability that is beyond the reach of their server cousins.

Mainframe Definition

A mainframe computer is a large computing device that runs complex operating systems, is extremely fast, consumes a large amounts of electricity and requires a clean, cool environment. Mainframes typically process mixed workloads very efficiently, serving thousands of users and processing batch transactions efficiently at the same time.

Mainframes Run Complex Operating Systems

While servers run Windows Server, Linux and UNIX operating systems, mainframe computers run extremely complex and powerful OSs such as MVS/XA, OS/390 and z/OS. These operating systems are capable of utilising the hardware to produce the required transaction volume, and can run the previously mentioned server OSs as well. Virtualisation is not as new as some may think, as it was introduced decades ago in mainframe operating systems.

Mainframes Are Large

Mainframe computers are larger than other computers, even the smallest taking up 10-12 square feet of floor space. The earliest mainframes such as UNIVAC and BRANIAC occupied hundreds of feet of floor space while ENIAC used 19,000 vacuum tubes and weighed over 27216 Kilogram. Modern mainframes take up far less space, but provide far more computing power than their ancestors.

Mainframes Are Very Fast

Mainframes are incredibly fast computing machines. Their processor speeds combine with their ability to manage storage and memory to provide maximum transaction throughput. This ability to handle large transaction volumes is what endears mainframe computers to large banks, governments and insurance companies. These companies need the processing power of mainframe computers to process huge numbers of transactions on a daily basis.

Mainframes Devour Electricity

The vacuum tubes used in early mainframes consumed large amounts of power, and while modern mainframes are smaller and use more efficient components, they still consume a lot of electricity. Additionally, mainframes rely on clean and constant power through power conditioning equipment and uninterrupted power supplies -- UPSs.

Mainframes Need Clean, Cool Air

Dust and heat can cause major damage to any computing components and mainframes are no exception. There is a lot of circuitry in a mainframe computer and that circuitry produces heat. Cool air is required to keep a mainframe from overheating, which means expensive air conditioning and ventilation. Some mainframes have thermal sensors that shut the machine down if the room reaches a set temperature. Static electricity causes dust to adhere to the chips in computing equipment, so it is imperative that a mainframe computer room be kept clean and as dust-free as possible.

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About the Author

Alan Hughes has more than 30 years of experience in IT including mainframes, programming, client/server, networks, project management, security, disaster recovery, information systems and hardware. He holds a master's degree in applied computer science and several certifications. He currently teaches information technology at the university level.