mainframe


Also found in: Dictionary, Thesaurus, Medical, Financial, Acronyms, Wikipedia.
Related to mainframe: COBOL, IBM mainframe

mainframe

1. 
a. a high-speed general-purpose computer, usually with a large store capacity
b. (as modifier): mainframe systems
2. the central processing unit of a computer
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

mainframe

(computer)
A term originally referring to the cabinet containing the central processor unit or "main frame" of a room-filling Stone Age batch machine. After the emergence of smaller "minicomputer" designs in the early 1970s, the traditional big iron machines were described as "mainframe computers" and eventually just as mainframes. The term carries the connotation of a machine designed for batch rather than interactive use, though possibly with an interactive time-sharing operating system retrofitted onto it; it is especially used of machines built by IBM, Unisys and the other great dinosaurs surviving from computing's Stone Age.

It has been common wisdom among hackers since the late 1980s that the mainframe architectural tradition is essentially dead (outside of the tiny market for number crunching supercomputers (see Cray)), having been swamped by the recent huge advances in integrated circuit technology and low-cost personal computing. As of 1993, corporate America is just beginning to figure this out - the wave of failures, takeovers, and mergers among traditional mainframe makers have certainly provided sufficient omens (see dinosaurs mating).

Supporters claim that mainframes still house 90% of the data major businesses rely on for mission-critical applications, attributing this to their superior performance, reliability, scalability, and security compared to microprocessors.
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)

mainframe

A state-of-the-art computer for mission critical tasks. Today, mainframe refers to a class of ultra-reliable servers from IBM that is designed for enterprise-class and carrier-class operations.

However, in the "ancient" mid-1960s, all computers were mainframes, since the term referred to the "main" CPU cabinet. The first mainframe vendors were (alphabetically) Burroughs, Control Data, GE, Honeywell, IBM, NCR, RCA and Univac, otherwise known as "IBM and the Seven Dwarfs." After GE and RCA's computer divisions were absorbed by Honeywell and Univac respectively, the mainframers were known as "IBM and the BUNCH."

IBM Is the Mainframe Vendor
For decades, IBM was the dominant vendor in the mainframe business. Although many tried to compete by offering compatible machines, they no longer do (see IBM-compatible mainframe). HP, Unisys, Sun and others make machines that compete with IBM mainframes in many industries but are mostly referred to as servers. In addition, non-IBM mainframe datacenters have hundreds and thousands of servers, whereas IBM mainframe datacenters have only a few machines.

There Is a Difference


One might wonder why mainframes cost hundreds of thousands of dollars when the raw gigahertz (GHz) rating of their CPUs may be only twice that of a PC costing 1,000 times less. Here's why:

Lots of Processors, Memory and Channels
Mainframes support symmetric multiprocessing (SMP) with several dozen central processors (CPU chips) in one system. They are highly scalable. CPUs can be added to a system, and systems can be added in clusters. Built with multiple ports into high-speed caches and main memory, a mainframe can address thousands of gigabytes of RAM. They connect to high-speed storage subsystems that can hold petabytes of data.

Enormous Throughput
A mainframe provides exceptional throughput by offloading its input/output processing to a peripheral channel, which is a computer itself. Mainframes can support hundreds of channels, and additional processors may act as I/O traffic cops that handle exceptions (channel busy, channel failure, etc.).

All these subsystems handle the transaction overhead, freeing the CPU to do real "data processing" such as computing balances in customer records and subtracting amounts from inventories, the purpose of the computer in the first place.

Super Reliable
Mainframe operating systems are generally rock solid because a lot of circuitry is designed to detect and correct errors. Every subsystem may be continuously monitored for potential failure, in some cases even triggering a list of parts to be replaced at the next scheduled maintenance. As a result, mainframes are incredibly reliable with mean time between failure (MTBF) up to 20 years!

Here to Stay


Once upon a time, mainframes meant "complicated" and required the most programming and operations expertise. Today, networks of desktop clients and servers are just as complex. Large enterprises have their hands full supporting thousands of PCs along with Windows, Unix and Linux and likely some Macs as well.

With trillions of dollars worth of IBM mainframe applications in place, mainframes may hang around for quite a while. Some even predict they are the wave of the future!


Mainframe System
Mainframes provided the computing power for major corporations for more than 50 years. Sperry Rand (Univac), IBM, GE, RCA, NCR, Burroughs, Honeywell and Control Data were the first companies to make mainframes in the U.S. This picture was taken in the mid-1970s. (Image courtesy of Unisys Corporation.)






UNIVAC Mainframe
Mainframes provided the computing power for major corporations for more than 50 years. Sperry Rand (Univac), IBM, GE, RCA, NCR, Burroughs, Honeywell and Control Data were the first companies to make mainframes in the U.S. This picture was taken in the mid-1970s. (Image courtesy of Unisys Corporation.)
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
The global Mainframe Development market has been studied for the forecast period by employing Porter's Five Force Model for the review period of 2019 to 2024.
Once applications are independent from the mainframe, Astadia works on ongoing optimization through refactoring and rewriting--alongside CI/CD and Automated Testing.
Not only will IBM likely get a revenue boost in 2020 thanks to the next mainframe launch, but the company will also add a few billion dollars of revenue from its acquisition of Red Hat.
According to Banham, mainframe customers must find ways to make MFA roll-outs easier and less onerous.
* Purpose-built views of the mainframe environment to monitor unexpected connections to mainframe servers.
Large enterprises are struggling to bring Agile and DevOps best practices to their core systems of record, which are written in COBOL and other codebases running on IBM Z mainframes. This mainframe transformation is essential-because their ability to compete with "digital first" market disrupters is largely contingent on their ability to continuously adapt back-end systems to ever-changing market realities.
Companies still rely on the mainframe to process their most important transactional data, but we're seeing an increased focus on integrating this data within Big Data analytics platforms to provide a complete enterprise-wide view of data for intelligence on business-critical operations, security breaches and compliance audits, said David Hodgson, General Manager of Syncsort's Mainframe business.
In addition, information orchestration offers what is often a more flexible, and more affordable, alternative to completely migrating off the mainframe. The approach also helps companies plug into the wealth of information on their mainframe-related systems such as customer information systems (for transaction information and spend history) and product information systems (for valuable pricing information and product description information).
Compuware empowers the world's largest companies to advance their mainframe intellectual property to meet the demands of the digital economy.
* On average, 33% of organizations' mainframe applications are accessible on mobile devices and in two years' time this number is expected to rise by 39%
Market research firm Vanson Bourne questioned 520 CIOs internationally about mainframe use in their enterprises, including 100 in the UK.
Overall, 84 programs in CA's integrated stack of 234 mainframe programs have been updated.