Mainframe Computer

What is Mainframe Computer?

A mainframe computer, also known as mainframe simply is the frame that holds a lot of processors and the RAM. Technically, a mainframe computer refers to a large and powerful system made with the combination of several processors and memory.

A mainframe computer also refers to the CPU of several terminals and workstations that are connected with it that allows several users to use it and run an entire organization.

Understanding Mainframe Computer

Mainframe Computer

Simply by the look and definition of it, a mainframe computer is a large centralized machine.

It has a much higher processing power in comparison to a standard computer due to its several high-grade processors and large memory.

Ideally, the name, ‘Mainframe’ is derived from the frame that holds the main memory and a number of processors.

Its high speed and processing power has increased its usability and importance in different sectors and fields such as:

With its ability to carry out several complex programs simultaneously, a mainframe computer can be used as the central processing unit of several terminals and workstations connected to it.

It can not only handle thousands of Petabytes of data but, at the same time, it can also handle thousands of users in real time.

Components of Mainframe Computer

The components of the mainframe computer play a big role in ensuring a high and fast performance.

Some of the major components of a mainframe computer are:


The Central Processing Unit or CPU that comes with:

All these channels work together as a medium for communication between the memory modules and the I/O terminal with the primary objective to manage the components of the entire system and to transfer data.

Control Unit

The CU or Control Unit, also known as the bus, in the mainframe computer is linked to the storage unit area.

There are different buses in the system that have varied usage such as tapes, disks, and others.

Storage Unit

The storing unit of a mainframe computer performs a lot of different tasks such as:

A storage unit may have several devices such as tape drives, hard drives, punch cards, and others with a capability that is million times faster than a normal computer, all of which are controlled by the CPU.


There is a multiprocessor unit in the mainframe computer.

This means that there are several processors that help in processing the multitude of data by using interrupt handling and error handling within a very short time frame.


The motherboard of the mainframe computer comes with a number of components in it such as:

All these use the bus architecture of it to perform.

I/O Channels

There are different I/O channels in a mainframe computer system that helps in performing specific techniques such as:

Cluster Controller System

This particular device of the mainframe computer typically, comes in two different variants such as:

The cluster controller system helps to attach the host terminal system and the channel terminal.

Functions of Mainframe Computer

A mainframe computer performs different functions that can be broadly divided into these main segments.


The mainframe computer was usually designed for offering raw computational speed but the modern machines are characterized less by it and more by:

Most importantly, the infrastructure necessities are now reduced drastically since the 1990s as compared to the design of the earlier mainframe computers.

This is because the older bipolar technology is replaced by the Complementary Metal Oxide Semiconductor or CMOS mainframe design.

However, the Return On Investment or ROI from a mainframe computer may not be same for all computing platforms because it is dependent on different factors such as:

However, the modern mainframe computers consume less energy, need less power and cooling, which is good for the large data centers in terms of cost.

The modern mainframe computers also need less physical space.

The usual impression of the user interface of a mainframe computer of an old CRT or Cathode Ray Tube green screen monitors with 80 x 24-character is replaced, In fact, the modern mainframe computers look pretty much like a UNIX system or a personal computer.


However, there are some disadvantages of the mainframe computers, which is why these machines are not usable for any normal user.

The high cost of these systems is not affordable for any normal user.

Also, it needs a different operating environment from a normal computer that should have low temperature and large and well ventilated space.

It also needs expert professionals for its maintenance and upkeep. If one component fails, the whole system will break down, which is a major setback for these computers.

The mainframe computers use a lot of resources as compared to regular computer systems which adds to the cost.

The fact that there is more than one operating system installed in a mainframe computer increases the complexity for the users to use the system and for the system to read the instructions.

Who Uses Mainframe Computers?

In spite of the disadvantages, which are mainly for the normal users, a mainframe computer is extensively used by the large scale organizations since these machines are able to carry out millions of transactions in a second.

These organizations typically need to deal with huge amounts of data every second.

And, surprisingly, even you as an individual use a mainframe computer!

Well, the Automated Teller Machine you use to draw money is an example of a mainframe computer.

The different sectors that use a mainframe computer are:

A mainframe computer can be used for all those mission-critical applications which include and are not limited to:

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Apart from that, most of the busiest websites use a mainframe host to store their magnanimous production databases.

When you access a business application through a web browser, it is often a mainframe computer that performs the vital functions behind the scenes.

Where and Why Mainframe Computers are Used?

Some of the major sectors where a mainframe computer has proved to be an integral part in their daily operations are:

In addition to the above, there are also some other areas of businesses where a mainframe computer is used to manage their huge customer database. These include and are not limited to:

The main reason that the businesses today rely heavily on a mainframe computer are:

As for the list of advantages it includes their perception of virtualization where the entire system is split into smaller logical segments to eliminate memory issues and increase performance levels.

These machines are self-serviceable which reduces the cost of maintenance by the businesses.

This means that these systems can identify the bugs and threats to it and recover from them.

Since the design of the mainframe computers is more flexible, it allows more customization to suit the requirement of every user with support provided to several operating systems at the same time.

Finally, it is the longevity, which is ideally up to 40 years, that is making the mainframe computers so favored and reliable in the business sectors today.

Types of Mainframe Computers

There are different types of mainframe computers of different brands that can be used in different sectors according to the user and computing requirements.

However, the major ones are:

Initially, IBM or the International Business Machines was the leading mainframe computer manufacturer but over time there are others who joined the bandwagon.

Features of Mainframe Computers

Some of the useful features of the mainframe computers that have made them so popular in those sectors that deal with larger data sets are:

However, in spite of all these useful features the terminals of the mainframe computers fail to produce a very high user experience because these systems are not designed for a typical end user.


The mainframe computers today are very useful for businesses and since you now know their utility and different types, you can easily choose a variety for your particular type of computing requirements.

Irrespective of whichever model you choose, rest assured to get a higher and faster performance.