Fundamentals of Computer > Introduction to Computer & Computer System > Classification of Computer according to Size, Cost, Processing Speed
Classification According to Size, Cost, Processing Speed etc.
Computer can be classified into four categories according to size, cost, processing speed, storage capacity, types of tasks they can handle, types of hardware they contain, kinds of software they can run etc. These are
- Super Computer
- Mainframe Computer
- Minicomputer
- Microcomputer
Super Computer:
These are the largest and the most powerful computers available today in terms of processing.
- Supercomputers have large memories and high processing speeds. They can process up to a billion of instructions (operations) per seconds.
- The high speed in these computers is due to use of a number of processors working in parallel (this is known as parallel processing) and high storage densities are obtained by using magnetic bubble memories.
- The primary disadvantage of supercomputer is their high cost. The software that runs on them is also very expensive.
Application: These computers are used for complex scientific purposes such as in nuclear fission, NASA, weather forecasting, defense research, space research etc.
Mainframe Computer:
Mainframe computers are larger than mini- and microcomputers and they usually have one or more central processors. They have many terminals connected to them.
- They can handle massive amount of input, output and storage.
- These computers are used where many people in a large organization need frequent access to the same information, which is usually organized into one or more huge databases. Here each user uses a terminal for accessing data into the mainframe computer.
We should remember that Atomic Energy Commission of Bangladesh used a mainframe computer in the early 1980s for the first time in Bangladesh.
Application: Mainframe computers are ideal for research organizations, large industries, bank and insurance company, government organizations and large-scale on line reservation systems.
Minicomputer:
These computers are smaller in size, and lower in cost than super- and mainframe computers but slightly bigger in size, memory and speed compared to microcomputers.
- Minicomputers are often referred as “mid-range computers” since their capabilities lie between those of mainframe and microcomputers.
- Minicomputers are multi-user system. This means that more than one user can use the computer system at the same time.
- These computers are ideal for those organizations and companies that cannot afford or don’t need mainframe systems.
Application: Minicomputers are widely used in industrial process control, bank and insurance company, engineering and scientific research etc.
Microcomputers:
A microcomputer consists of a main microprocessor (a CPU on a chip), several support microprocessors, and associated control unit, primary storage, secondary storage and a variety of input/output devices.
- It is called micro because of its miniature size and using of microprocessor.
- These are the smallest and cheapest category of digital computers, which are widely used in the world.
- Computers of this category are supported by single-user operating system.
Microcomputer is further subdivided into-
- Home computers (used for entertainment, education, training and for home management )
- Personal computers (PC, used by only one person at a time)
- Personal computers can be further subdivided into Desktop, Laptop, Palmtop etc.