A state-of-the-art computer for mission critical tasks. In the "ancient" mid-1960s, all computers were mainframes, since the term referred to the main CPU cabinet. Today, it refers to a class of ultra-reliable medium and large-scale servers designed for enterprise-class and carrier-class operations.
The first mainframe vendors were 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."
The Vendors
For decades, IBM has been the dominant vendor in the mainframe business. Although many tried to compete by offering IBM-compatible mainframes, only Amdahl (Fujitsu) has remained as a competitor in this arena (see IBM-compatible mainframe). Unisys, Sun and others also make mainframe-class machines that typically run under a version of Unix or Linux.
There Is a Difference
One might wonder why mainframes cost a million dollars or more when the raw gigahertz (GHz) rating of their CPUs is not any higher than a PC costing 1,000 times less. Quite often in fact, the ratings are lower. Here are the reasons.
Lots of Processors, Memory and Channels
Mainframes support symmetric multiprocessing (SMP) with several dozen central processors 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 disk subsystems that can hold terabytes 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, if not more so. Large enterprises have their hands full supporting thousands of PCs along with Windows, Unix and Linux and maybe some NetWare and Macintosh for good measure.
With trillions of dollars worth of mainframe applications in place, mainframes may hang around for quite a while. Some even predict they are the wave of the future! See midrange computer.
Mainframe System
UNIVAC Mainframe
Mainframes have provided the computing power for major corporations for more than 40 years. Sperry Rand (Univac), IBM, GE, RCA, NCR, Burroughs, Honeywell and Control Data were the first companies that made mainframes in the U.S. This picture was taken in the mid-1970s. (Image courtesy of Unisys Corporation.)
The first mainframe vendors were 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."
The Vendors
For decades, IBM has been the dominant vendor in the mainframe business. Although many tried to compete by offering IBM-compatible mainframes, only Amdahl (Fujitsu) has remained as a competitor in this arena (see IBM-compatible mainframe). Unisys, Sun and others also make mainframe-class machines that typically run under a version of Unix or Linux.
There Is a Difference
One might wonder why mainframes cost a million dollars or more when the raw gigahertz (GHz) rating of their CPUs is not any higher than a PC costing 1,000 times less. Quite often in fact, the ratings are lower. Here are the reasons.
Lots of Processors, Memory and Channels
Mainframes support symmetric multiprocessing (SMP) with several dozen central processors 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 disk subsystems that can hold terabytes 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, if not more so. Large enterprises have their hands full supporting thousands of PCs along with Windows, Unix and Linux and maybe some NetWare and Macintosh for good measure.
With trillions of dollars worth of mainframe applications in place, mainframes may hang around for quite a while. Some even predict they are the wave of the future! See midrange computer.
Mainframe System
UNIVAC Mainframe
Mainframes have provided the computing power for major corporations for more than 40 years. Sperry Rand (Univac), IBM, GE, RCA, NCR, Burroughs, Honeywell and Control Data were the first companies that made mainframes in the U.S. This picture was taken in the mid-1970s. (Image courtesy of Unisys Corporation.)
 | Reproduced with permission from Computer Desktop Encyclopedia. Copyright (c) 1981-2008 The Computer Language Company Inc. All rights reserved. |
Additional Resources
- Windows Vista, meet my Mother-In-Law.
- Windows Vista, meet my Mother-In-Law.Truth must be toldYou have to be honest with her. Just tell her the truth and she will understand. It might take a longer time but once she knows how to use a PC I bet you she will get the point.Try this:The computer is fine....
- Discussion threads 2008-06-30
- From Chapter one: Data Processing and the IBM Mainframe
- From Chapter one: Data Processing and the IBM MainframeFault toleranceIn these two quotes, discovering a difference in word usage leads to impacable hostility:Talk about vouchers to someone in Payroll and you won’t be sharing any understanding of the term as it is used in Accounts Payable; and, of course, the...
- Discussion threads 2008-06-27
- News to know: ICANN hacked; IE flaw; OpenSuse 11; Hyper-V; iPhone 3G
- Notable headlines: Ryan Naraine: Zero-day flaw haunts Internet Explorer Tech heavyweights launch security response consortium ICANN and IANA's domains hijacked by Turkish hacking group Security researchers hack the London underground train for free ride Matthew...
- Blog posts 2008-06-27
- From Chapter one: Data Processing and the IBM Mainframe
- CICS and IMS, IBM's two of IBM's three original software products are still going strong - and so is the culture that adopted them in 1969. by Paul Murphy
- Blog posts 2008-06-27
- From CFrom Chapter one: Data Processing and the IBM Mainframe
- From CFrom Chapter one: Data Processing and the IBM MainframeDitch all this Cr@p!They need to simply go with Vista Server and MS Access 2008 Server! Problem solved!http://fakesteveballmer.blogspot.comRE: From CFrom Chapter one: Data Processing and the IBM MainframePlease bear in mind that the 360 came out ten years before the ideas...
- Discussion threads 2008-06-20
- From Chapter one: Data Processing and the IBM Mainframe
- COBOL reflects 1920s data processing methods - and because the IBM 360 implemented COBOL it became the foundation for an entire worldview - a culture founded entirely on a refusal to adapt to external change: in technology, in the mission, in anything. by Paul Murphy
- Blog posts 2008-06-20
- IT catfight in Portland, OR
- IT catfight in Portland, ORSacraficeMy company just finished an ERP release, successfully!It takes whole company sacrifice and requires separate Change Management groups to come to power to lead staff and executive management with the project and the temporary sacrifices in business process and political ownership. It takes years of...
- Discussion threads 2008-06-19
- TextPipe (exe)
- A powerful text-processing tool that combines more than 100 translation, conversion and filtering operations on multiple binary files or text files. Update text using search and replace, which supports perl pattern matching, sounds-like matching, edit-distance matching and search/replace lists. Convert files from foreign computer systems between mainframe fixed-length formats and...
- Software downloads 2008-06-17
- From Chapter one: Data Processing and the IBM Mainframe
- From Chapter one: Data Processing and the IBM Mainframeumm, good pointI'll change it to electro-mechanical.Thanks!possible error?[i]It was the first successful system designed “from the ground up” to advance automated data processing by replacing the physical cards and associated electro-mechanical gear with purely digital processing and magnetic tape or disk storage,...
- Discussion threads 2008-06-13
- From Chapter one: Data Processing and the IBM Mainframe
- The nature of data processing is to be long winded, boring, and dominated by acronyms derived from long gone technologies and business practices. by Paul Murphy
- Blog posts 2008-06-13
- Cloud computing meets capitalism: We all become a business of one
- Folks spend a lot of time talking about cloud computing. It's a move back to the mainframe. Cloud computing democratizes IT infrastructure. The cloud will be the reason Amazon and Google will be the dominant players on the Internet. You have heard a lot of it before. But the real...
- Blog posts 2008-06-10
- BIt: From Chapter one: Data Processing and the IBM Mainframe
- BIt: From Chapter one: Data Processing and the IBM MainframeReading this gives me the shakes......by bringing back my days at the Chubb Institute in 1991, learning BASIC, OS JCL & COBOL. MANY hours of flow charting...WITH PENCIL & PAPER...and many more hours at a terminal trying to get what I...
- Discussion threads 2008-06-06
- BIt: From Chapter one: Data Processing and the IBM Mainframe
- From Chapter one: Data Processing and the IBM Mainframe This is the 4th excerpt from the second book in the Defen series: BIT: Business Information Technology: Foundations, Infrastructure, and Culture Note that the section this is taken from, on the evolution of...
- Blog posts 2008-06-06
- Quest Software - Embracing, extending, simplifying
- Quest Software has been acquiring other management software companies rapidly over the past year or so. This includes companies such as Provision Networks, Vizioncore, ScriptLogic. I recently had a conversation with company representatives to learn more about the strategic plan behind those acquisitions. I must admit that before I had...
- Blog posts 2008-06-05
- Virtualizing onto mainframes: How to make it fit
- Virtualizing onto mainframes: How to make it fitOne day...I'm hoping virtualisation will be better by really virtualising an existing machine using the same hardware drivers etc. That way, if you're using the vitualisation for testing, you can just ghost the real machine with the virtual one once its working.Apparently,...
- Discussion threads 2008-06-04
- Microsoft Webcast: Reducing Total Cost of Ownership by Transforming Natural and ADABAS Applications to the .NET Framework (Level 200)
- Representatives from Microsoft and BluePhoenix explain how one can reduce the Total Cost of Ownership TCO by modernizing the Natural and ADABAS applications through the automated BluePhoenix process. Discover how to reduce license and maintenance costs, reduce infrastructure costs, and eliminate the IT resource problem, and increase application performance and...
- Webcasts 2008-06-03
- BIT: From Chapter one: Data Processing and the IBM Mainframe
- BIT: From Chapter one: Data Processing and the IBM MainframeThe function, then the how.A discussion beginning: State population totals were derived from individual census tract results by... would create a context. As a narrative strategy, reaching a goal is more organized, satisfying, than describing a process and giving...
- Discussion threads 2008-05-30
- News to know: Google Apps; Vista UAC; Microsoft Echoes; Comcast; Dell
- Notable headlines: Garett Rogers: Google App Engine pricing a disappointment Ed Bott: Dear Microsoft: Please get UAC right this time Sunbelt Blog: Microsoft: What we got here is a failure to communicate Larry Dignan: Dell delivers: Is a...
- Blog posts 2008-05-30
- BIT: From Chapter one: Data Processing and the IBM Mainframe
- This is the 3rd excerpt from the second book in the Defen series: T Business Information Technology: Foundations, Infrastructure, and Culture Roots part One Herman Hollerith, then a statistician with the US bureau of the Census formed a company called...
- Blog posts 2008-05-30
- Google bets future on improving Client, Connectivity, and Cloud
- On Wednesday morning, Vick Gundotra, Engineering VP at Google opened the Google I/O developer's conference in San Francisco. I jotted down a few (ok, a lot of) notes for this and other sessions that I'd like to share with you. This is not quite a transcript, but rather a paraphrasing...
- Blog posts 2008-05-29
Neighboring Terms
Premier Vendor Content Whitepapers, webcasts & resources from our Power Center Sponsors
- New entries posted to Know Issues, Best Practices and Workarounds Wiki
-
Latest Topics: Running virtual machines and DHCP can cause Intel® AMT to be inaccessible; Wildcard certificates are currently not supported for remote; Dell 755 returns a duplicate UUID during activation configuration.
- See the latest entries on the Intel Wiki >>
- ZDNet News Videos
-
Tech news covering the latest in products, conferences and blog commentary, from ZDNet video.
- Watch the latest video >>
- The Cisco Mobility Resource Center is your source for FREE mobility solutions
-
The Cisco Mobility Resource Center offers FREE videos, downloads, podcasts and more, all designed to help small and medium businesses get mobile connectivity solutions, improve productivity and drive sales and revenue.
- New mobility solutions at the Cisco Mobility Resource Center
-
-
Tasty Baking’s new LEED factory
0:57
Tasty Baking CIO: Brendan O’Malley
-
Balancing act: innovation vs. reliability
1:28
Facebook VP of technical operations: Jonathan Heiliger
-
Securing data at E-Loan
1:47
E-Loan CIO: Jay Shah
-
When crops are scarce
1:47
Del Monte Foods CIO: Marc Brown
- View all CIO Vision Series Videos »
