Four types of computers

Since the advent of the first computer different types and sizes of computers are offering different services. Computers can be as big as occupying a large building and as small as a laptop or a microcontroller in mobile & embedded systems.

The four basic types of computers are as under:


The most powerful computers in terms of performance and data processing are the Supercomputers. These are specialized and task-specific computers used by large organizations. These computers are used for research and exploration purposes like NASA uses supercomputers for launching space shuttles, controlling them, and for space exploration purposes.

The supercomputers are very expensive and very large in size. It can be accommodated in large air-conditioned rooms; some super computers can span an entire building.

Seymour Cray designed the first Supercomputer “CDC 6600” in 1964. CDC 6600 is known as the first ever Supercomputer.


Processing Units

The processing power of a supercomputer can range from several hundred thousand to a million and more. Massively parallel computing is performed when two processors work in tandem, or a GPU, depending on the architecture. Known as capability computing, this is what makes supercomputers unique from regular computers. Having a processor speed measurement of computer performance became obsolete as a result of this feature. FLOPS, short for Floating Point Operations Per Second, are the measures of a supercomputer’s performance. The multiplication and division of floating-point numbers are meaningless mathematically without them. In fact, multiplication and division are actually more computationally intensive than addition and subtraction. Clusters of HPC computers now boast scalability and processing power that are impressive as well.

Memory Units

The sheer size of the random-access memory (RAM) of a supercomputer is merely the first element in determining its memory capacity. Nodes are super high-performance computers, which have many processing units or cores, however, even while distributed over many nodes. The RAM modules on supercomputers can be considered as a single pool. With the help of specialized software, middleware, the RAM modules can work together. The RAM on supercomputers is sometimes in the terabyte range. Additionally, the supercomputer’s memory also has the unique feature of being addressable by all its processing units. Processing units make it as capable as they come of solving complex mathematical problems.

Interconnect Among Nodes

In a supercomputer, multiple nodes are linked together via switches that operate at high speeds. Imagine each of these nodes as a massive computer. Nodes are connected in a nonblocking fat-tree topology to ensure high throughput, delivering up to 200Gb/s bandwidth between them. Furthermore, communication frameworks (MPI) can be accelerated in-network. The use of high-speed interconnections (bandwidth and latency) is quite a characteristic of supercomputers. For their massive amounts of CPUs and RAM to be fully utilized, they need a high-speed interconnect.

File systems speed & High input/output

Supercomputers offer the speed of computations, as well as the capability of writing and reading data. GPFS and Lustre are both examples of parallel file systems that are used for this purpose. Another important aspect of supercomputers is their ability to read and write data quickly.

Specialized Support

We tend to visualize only the machine when we envision a supercomputer. Supercomputers are underrated for one of their most important aspects – their support staff. The IT community is made up of dozens of brilliant professionals working tirelessly to develop innovative solutions. These complex systems need to be constructed in such a way that they provide the highest computing performance and produce the highest production standards.

Thermal Management

High performance supercomputers need to maintain the high cooling efficiency of the processors and auxiliary components. For optimal cooling of supercomputers, liquid coolers, hot water coolers, and immersion coolers must be incorporated. The CPUs are always functioning at full capacity if they are kept below their throttle temperatures. In terms of performance, processors perform best if they are not overheated by crowded systems, improper ventilation, or inadequate cooling.

Exascale Supercomputer

On 29th July 2015, President of the United States, Barack Obama, approved the development of an Exascale Super Computer. The Exascale Supercomputer will be 30 times faster and more powerful than today’s fastest Super Computers. The need to develop such a high-performance Supercomputer comes after China’s surge in high performance computing. However, the US still tops the list of Supercomputers with 233 high-performance machines. China has 37 Supercomputers but they lead the list of the most powerful and high performance supercomputers since June 2013.

Presently, China’s “Tianhe – 2” is the world’s faster Supercomputer.

The Tianhe – 2 can perform 100 Petaflops, i.e quadrillions of floating point operations per second.

The following table shows list of top five most powerful Supercomputers in the world.

1 National Super computer in Guanzhou, China Tianhe – 2 (MilkyWay – 2) 3,120,000 33,862.7 54,902.4 17,808
2 DOE/SC/Oak Ridge National Laboratory, United States Tianhe – 2 (MilkyWay – 2) 560,640 17,590.0 27,112.5 8,209
3 DOE/NNSA/LLNL, United States Tianhe – 2 (MilkyWay – 2) 1,572,864 17,173.2 20,132.7 7,890
4 RIKEN Advanced Institute for Computational Science (AICS) Japan Tianhe – 2 (MilkyWay – 2) 705,024 10,510.0 11,280.4 12,660
5 DOE/SC/Argonne National Laboratory, United States Tianhe – 2 (MilkyWay – 2) 786,432 8,586.6 10,066.3 3,945

Uses of Supercomputers

In Pakistan, Supercomputers are used by Educational Institutes like NUST for research purposes. Pakistan Atomic Energy commission & Heavy Industry Taxila uses supercomputers for Research purposes.

Space Exploration

Supercomputers are used to study the origin of the universe, the dark-matters. For these studies scientist use IBM’s powerful supercomputer “Roadrunner” at National Laboratory Los Alamos.

Earthquake studies

Supercomputers are used to study the Earthquakes phenomenon. Besides that supercomputers are used for natural resources exploration, like natural gas, petroleum, coal, etc.

Weather Forecasting

Supercomputers are used for weather forecasting, and to study the nature and extent of Hurricanes, Rainfalls, windstorms, etc.

Nuclear weapons testing

Supercomputers are used to run weapon simulations that can test the Range, accuracy & impact of Nuclear weapons.

Popular Supercomputers

  • IBM’s Sequoia, in United States
  • Fujitsu’s K Computer in Japan
  • IBM’s Mira in United States
  • IBM’s SuperMUC in Germany
  • NUDT Tianhe-1A in China

Mainframe computer

Although Mainframes are not as powerful as supercomputers, certainly they are quite expensive nonetheless, and many large firms & government organizations use Mainframes to run their business operations. The Mainframe computers can be accommodated in large air-conditioned rooms because of their size. Super-computers are the fastest computers with large data storage capacity, Mainframes can also process & store a large amounts of data. Banks educational institutions & insurance companies use mainframe computers to store data about their customers, students & insurance policy holders.


The mainframe computer system is composed of several major components that contribute to its outstanding performance.

Processing Unit

Each CPU has its own printed circuit board, memory module, processor, and interface for each channel. Every communication channel functions as a connection between the input/output terminal and the memory module. All of these channels are primarily used for data transmission and management.

Controller Unit

The controller unit is also referred to as a bus. There are several buses installed in mainframe computers for various devices, such as tapes, disks, etc. Additionally, the storage unit is linked to the bus system.

Storage Unit

Storage units perform a variety of functions, such as storing, retrieving, and accessing data. Hard drives, tape drives, punch cards, and other devices are located in the storage unit, and they are all controlled by the CPU. The capacity of these devices is a million times greater than that of PCs.


Computers equipped with mainframes typically have multiple processors. It means that they can process massive amounts of information fast using error detection and interrupt handling.


In addition to the processors, memory (RAM), and other hardware components found on the motherboard, it also contains other components. Through its bus architecture, the motherboard performs its functions. Here, a 128-bit bus is implemented in the motherboard.

Cluster Controller System

Channel terminals are linked to host terminal systems through this device. A cluster controller can be channel-attached or linked-attached depending on whether it is attached directly to a channel or to a link.

Input/Output Channels

Among the techniques used in mainframe computers are IOCDS, ESCON, FICON, CHIPD, and others.

ICODS – ICODS full form is I/O Control Data Set.

ESCON – ESCON full form is Enterprise Systems Connection.

FICON – FICON full form is Fiber Connector.


Here are descriptions of each segment of a mainframe computer’s working.

Data Warehouse System

The hard disk is a standard component in every computer so that data can be stored for long periods of time. However the mainframe computer stores the whole data as software within its body. The central computer allows all remote terminals for accessing all files and programs that are owned by all users attempting to log in from remote terminals connected to it.

Preserve Authentication Access

When all data and program files are stored in a mainframe, that can improve the productivity and efficiency of this system. Administrations have the ability to insert all applications and data on a mainframe system. Administrators are able to specify how many users have access to the information. Therefore, mainframe systems have great security against damaging intruders’ attacks.

Allot Processor Time Frame

The mainframe computer system has a limited amount of processing time that must be divided among all users currently connected to the system. A mainframe system determines which types of priorities are assigned to which types of users. It is up to the administrator to determine how to allocate processor time to users.

Popular Mainframe computers

  • Fujitsu’s ICL VME
  • Hitachi’s Z800


Minicomputers are used by small businesses & firms. Minicomputers are also called “Midrange Computers”. These are small machines and can be accommodated on a disk with not as processing and data storage capabilities as super-computers & Mainframes. These computers are not designed for a single user. Individual departments of a large company or organization use Mini-computers for specific purposes. For example, a production department can use Mini-computers for monitoring the certain production process.

Popular Minicomputers

  • K-202
  • Texas Instrument TI-990
  • SDS-92
  • IBM Midrange computers

Things you May Know:

What is Mini PC?

A mini PC is also known as a minicomputer or mid-range computer. The form factor is similar to that of a large computer, but smaller because it has many of the same features and capabilities.

How do mini PC works?

The central processing unit (CPU) and memory of a mini PC are similar to those of a computer. Therefore, a mini PC functions similarly to a computer. A CPU executes an instruction by reading it from memory, then performing an operation on it using an ALU, then saving the result to memory.


There are a few differences between a mini PC and a computer; let’s take a look.


The processor performs operations depending on data. In general, mini PCs use low-power CPUs based on the (ARM) architecture, due to their small size and energy efficiency.


Memory is used to stores information. A computer’s memory may be divided into two types–read-only memory (ROM) and random-access memory (RAM). However, ROM cannot be modified, while RAM can be utilized in a variety of ways.


Considering the speed at which technology moves, storage has come a long way. Flash memory was designed to store and retrieve our data as easily as a USB thumb drive. Its modules are rather small but offer huge capacity.

Operating System

An operating system is any kind of software that helps a computer, smartphone or another computing device to perform basic tasks like running and managing programs, keeping track of a list of files and accessing the hardware of the system. Most operating systems today are very advanced, able to multitask several jobs at once, and offer easy ways to connect over the Internet.

Computer ports

It allows connections to other devices, such as keyboards, monitors, etc. Additionally, the mini PC may have RCA-video out, USB port, HDMI port, or audio jack.

Missing Features:

Cooling System

Having a mini PC generates heat, so you could potentially face this problem. However, you could always add a fan if you’re concerned.

Real-Time Clock (RTC)

Timekeeping devices such as RTC continue to work even after you shut them down. As a mini PC lacks a battery, and since an RTC also requires power from a battery, it was not included due to space constraints.

Physical Interface

It is necessary to purchase a monitor, keyboard and mouse with your purchase because mini PCs lack such features, but some of them do support Bluetooth. Alternatively, you can always use the USB port to connect.


There are several obvious advantages to mini PCs over laptops and desktops:


Since the name “mini” already gives you that information, it shouldn’t surprise you. Due to its small size and lightweight, it is both portable and easy to tuck away thanks to its compact dimensions.


Mini-computers are definitely much more cost-effective than desktops and laptops when compared with the price of desktops and laptops.


There are other benefits, too, such as the ability to replace the parts in a mini PC at any time, not to mention the ability to choose the monitor you wish to use, whether it is a TV or a computer monitor.

Energy Consumption

These small portable computers are known for their great energy efficiency, which means that less power is required to run them.


Desktop computers, laptops, personal digital assistants (PDA), tablets & smartphones are all types of microcomputers. Micro-computers are widely used & the fastest growing computers. These computers are the cheapest among the other three types of computers. The Micro-computers are specially designed for general usages like entertainment, education, and work purposes. Well-known manufacturers of Micro-computer are Dell, Apple, Samsung, Sony & Toshiba.

Desktop computers, Gaming consoles, Sound & Navigation systems of a car, Netbooks, Notebooks, PDA’s, Tablet PCs, Smartphones, Calculators are all types of Microcomputers.


The numerous features of microcomputers make them more valuable, including –


They are less expensive than mainframes and supercomputers. A mainframe computer is more powerful than a microcomputer or a workstation, but less powerful than a supercomputer. A mainframe computer can perform two or more tasks simultaneously.


In addition to handhelds, notebooks, laptops, tablets, portables, and desktops, microcomputers are also available in a wide range of sizes and shapes for various applications. In addition to residential and professional systems, workstations and multiuser systems can be categorized according to their intended usage. A microcomputer is either a desktop computer that sits on a desk or a laptop for individuals who prefer a portable computer.

Easy to Use

The single-user operation, no intensive training required. For the basic alphabet, punctuation marks, and Arabic numerals, nearly all microcomputers utilize the ASCII format. The number of designations available for other types of characters, such as graphics characters and control characters, also varies considerably.

Power Consumption

It consumes less power. Several processes are optimized at the same time. Gigabytes are measurements of storage capacity.


The chip consists of just one integrated circuit. Many toy companies have marketed simple microprocessor-based games, such as “Othello,” “baseball,” and “vehicle racing.”. Advancements in technology, such as Atari’s Video Computer System (USA), made microchips significant.

Processing Unit

This will reduce the processing power of the computer. This is far slower than small computers in terms of speed and processing power in comparison with them.

Heat Produce

Heat up less. Newer microcomputers have larger registers, so they can process 16 or 32 bits at a time.

Real-time Data

It is common for microcomputers to be portable. A system of data gathering in real-time can be established using standard microcomputers.


There are many software programs that can run on a microcomputer. The most popular versions of these computers are the IBM PC and Apple Macintosh. It is impossible to run IBM PC programs on Apple Macs and vice-versa because the operating systems are different.

Components of Micro-Computers

The basic components of a microcomputer are:

Central Processing Unit

There are three components to a CPU:

  • Arithmetic and Logic Unit (ALU)
  • Register Unit
  • Control Unit

The CPU also retrieves program instructions and data words from memory as well as reading data from memory and storing it in memory.

  • a) ALU (Arithmetic and Logic Unit)

    This unit performs mathematical and logical operations on data. Taking these functions as an example, arithmetic operations like additions, subtractions, and logical operations like ANDs, ORs, rotations, etc. In either case, the result is either stored in a register or a memory or sent to an output device.

  • Register Unit:

    This unit consists of various registers. A register is primarily utilized for storing data temporarily while a program is being executed. Instructions may be used to access some registers.

  • Control Unit:

    All of the microcomputer’s operations are controlled by this device which provides timing and control signals. A data flow network is a communication network between a computer and peripherals (input, output, memory). Several clocks are provided to the controller, which determines the speed.

Program Memory

Microcomputers are responsible for ensuring that their CPU executes the desired instructions as specified in the program. Initialization involves starting an instruction sequence in the program memory. This is usually achieved by switching on the processor and resetting it. The instruction is subsequently executed in the predetermined location. This should be the first instruction of a typical P-based system. The program to be executed is a fixed program that does not vary. ROM, therefore, contains only the monitor program, and all other programs are stored on EPROM, EPROM, or PROM. Since the user program does not have to be permanently stored in ROM, it is not kept in ROM.

Data Memory

Microcomputers manipulate data based on the instructions in the program stored in the program memory. The functional blocks in c have the same internal register for these instructions, which might need to store intermediate results. If the storage requirements are greater, external data memory can also be used if it’s available for that purpose. Furthermore, data memory can be used for storing results from programs, in addition to storing intermediate storage. Besides storing programs, data memory serves as a general storage region. Accordingly, they must have the capability to write to an RWM or RAM. It contains information on both the instructions that must be followed (i.e. program) and the information that must be processed. Memory is usually provided as ROM (Read-Out Memory). ROMs can only be read and cannot be written to, as well as being nonvolatile, meaning their contents are retained even after power is turned off. Data and instructions that are not likely to change are typically stored in ROM.

Input/Output Ports

Input and output ports allow the computer to interact with the rest of the world. An input port allows data to be passed from outside the computer to the central processing unit (CPU), which takes the data and transforms it to send it to the output device. Input devices such as keyboards, switches, CRTs, tape and card readers, or disk devices can be used to input (i.e. program) and data into memory. Temperature, pressure, speed, and other physical quantities can also be measured and controlled through computers. These signals are converted into digital signals by A/D computers that digitize electrical signals for the computers to process. Transducers are used to handle the conversion of physical quantities into proportional electrical signals. A computer transmits the results of a computation to an output device, such as a LED, CRT, D/A converter, or printer. These peripherals, which are called I/O devices, enable connectivity to the outside world.

Clock Generator

Typically, both within the c and in other parts of the c, operations are synchronous. Microprocessor instruction execution takes place during the appropriate clock periods generated by the clock generator. As a result of this condition, the paths of the systems can progress in a systematic manner. Many microprocessors are equipped with a clock generator circuit for generating a time signal. The operating frequency of these microprocessors is determined by an external crystal or operating frequency network (e.g. 8085). A clock generator may be necessary for certain microprocessors (e.g. 8086). Other components of the microcomputer system can use the output clock signal from these microprocessors to time and synchronize their operation.

Final Words

Nowadays, the need for computers has increased very much. In order to meet this increase in demand for computers, we have developed different types of computers for computations and other activities at home and business establishments to use. There is some computer which is used by very large organizations or organization but others used by everyone. So we can say that there are various types of computers like microcomputers, minicomputers, mainframe computers and supercomputers. The variety of computers used depends upon the work you do so choose the perfect one based on your needs and your work.