Factors Affecting Processing Speed

In the modern days competitive world, quick result is the most. We are moving so fast in our day to day life that we want to get results quickly. We use computer to perform various certain task quickly & accurately so that we can get our work done. But there are many factors that could affect the computer system & give us very poor result beyond our expectation. Some of the Factor that can affect our computer system are discussed below:

1. Registers
2. RAM
3. The System Clock
4. The Bus
5. Cache Memory

 

1. Registers

• The CPU contains of small memory areas:called registers,which store data and instructions while the CPU processes them.
• The size of the registers determines the amount of data with which the computer can work at a one time.
• Today most PC`s have 32-bit registers,mean the CPU can process four bytes data at one time.Register sizes are rapidly growing to 64 bits.

2. RAM

• The amount of RAM in a PC has a direct affect on the system`s speed.
• The more RAM a PC has.the more program instructions and data can be held in memory,which is faster than storage on disk.
• If a PC does not have enough memory to run a program,it must move data between RAM and the hard disk frequently.This process called swapping,can greatly slow a PC`s performance. 

3. The System Clock

• The computer`s system clock sets the pace the CPU by using a vibrating quartz crystal.
• A single "tick" of the clock is the time required to turn a transistor off and back on.This is called a clock cycle.
• Clock cycles are measured in Hertz(Hz),a measure of cycles per second.If a computer has a clock speed of 300 MHz, then its system clock"ticks" 300 million times every seconds.
• The faster a PCs clock runs,the more instructions the PC can execute each second.

4. The Bus

• A bus is a path between the components of a computer.Data and instructions travel along these paths.
• The data bus width determines how many bits can be transmitted between the CPU and other devices.
• The address buss runs only between the CPU and RAM, and carries nothing but memory addresses for the CPU to use.
• Peripheral devices are connected to the CPU by an expansion bus.

5. Cache Memory

• Cache memory is high-speed memory that holds the most recent data and instructions that have been loaded by the CPU.
• Cache is located directly on the CPU or between the CPU and RAM,making it faster than normal RAM.
• CPU-resident cache is called Level-1 (L1)cache.External cache is called Level-2 (L2) cache.
• The amount of cache memory has a tremendous impact on the computer`s speed.

Component of Digital Computer System

Central Processing Unit:
The control unit, memory unit and ALU of the computer are together known as the Central Processing Unit (CPU). The CPU is like brain performs the following functions:
• It performs all calculations.
• It takes all decisions.
• It controls all units of the computer.
A PC may have CPU-IC such as Intel 8088, 80286, 80386, 80486, Celeron, Pentium, Pentium Pro, Pentium II, Pentium III, Pentium IV, Dual Core, and AMD etc.

a) Control Unit:
It controls all other units in the computer. The control unit instructs the input unit, where to store the data after receiving it from the user. It controls the flow of data and instructions from the storage unit to ALU. It also controls the flow of results from the ALU to the storage unit. The control unit is generally referred as the central nervous system of the computer that control and synchronizes its working.

b) Arithmetic Logical Unit:
All calculations are performed in the Arithmetic Logic Unit (ALU) of the computer. It also does comparison and takes decision. The ALU can perform basic operations such as addition, subtraction, multiplication, division, etc and does logic operations viz, >, <, =, ‘etc. Whenever calculations are required, the control unit transfers the data from storage unit to ALU once the computations are done, the results are transferred to the storage unit by the control unit and then it is send to the output unit for displaying results.

c) Memory Unit:
The memory unit of the computer holds data and instructions that are entered through the input unit, before they are processed. It preserves the intermediate and final results before these are sent to the output devices. It also saves the data for the later use. The various storage devices of a computer system are divided into two categories.

1. Primary Storage: 

Stores and provides very fast. This memory is generally used to hold the program being currently executed in the computer, the data being received from the input unit, the intermediate and final results of the program. The primary memory is temporary in nature. The data is lost, when the computer is switched off. In order to store the data permanently, the data has to be transferred to the secondary memory.
The cost of the primary storage is more compared to the secondary storage. Therefore most computers have limited primary storage capacity.
2. Secondary Storage: 

Secondary storage is used like an archive. It stores several programs, documents, data bases etc. The programs that you run on the computer are first transferred to the primary memory before it is actually run. Whenever the results are saved, again they get stored in the secondary memory. The secondary memory is slower and cheaper than the primary memory. Some of the commonly used secondary memory devices are Hard disk, CD, etc.

Memory Size:
All digital computers use the binary system, i.e. 0’s and 1’s. Each character or a number is represented by an 8 bit code.
The set of 8 bits is called a byte.
A character occupies 1 byte space.
A numeric occupies 2 byte space.
Byte is the space occupied in the memory.

The size of the primary storage is specified in KB (Kilobytes) or MB (Megabyte). One KB is equal to 1024 bytes and one MB is equal to 1000KB. The size of the primary storage in a typical PC usually starts at 16MB. PCs having 32 MB, 48MB, 128 MB, 256MB memory are quite common.

Component of Digital Computer System

Inroduction

System is the group of computer parts that are integrated for the purpose of achieving objectives like processing of  data, pictures, sound and graphics & can solve highly complicated problems quickly and accurately. Computer is a group of integrated parts that have a common purpose of performing the operations called program, which can help to run computer system smoothly. Various computer peripherals connected to do some work called computer system.

Input Unit
Computers need to receive data and instruction in order to solve any problem. Therefore we need to input the data and instructions into the computers. The input unit consists of one or more input devices. Keyboard is the one of the most commonly used input device. Other commonly used input devices are the mouse, floppy disk drive, magnetic tape, etc. All the input devices perform the following functions:

• Accept the data and instructions from the outside world.
• Convert it to a form that the computer can understand.
• Supply the converted data to the computer system for further processing. 

Output Unit
The output unit of a computer provides the information and results of a computation to outside world. Printers, Visual Display Unit (VDU) are the commonly used output devices. Previously CRT monitor was used as VDU, now-a-days LCD monitors are widely in practice. Other commonly used output devices are floppy disk drive, hard disk drive, and magnetic tape drive.

 

Types of Computer

3. On the Basis of Model

On the basis of model computer is classified as:

XT (Extended / Extra Technology) Computer
The computers that use 8086, 8088 microprocessor are called XT computers. The time periods for this computer are from 1975 - 1982. XT computers have processing speed of 4.77 MHz and are comparatively slow in speed. These processors are of 4, 8 or 16 bits of word length.

AT (Advanced Technology) Computer
With the development of 80286 microprocessor AT computer were introduced in the field of computers. The processors are of 8, 16, 32 or 64 bits of word length. The computers using Pentium I, Pentium pro & Pentium II are the examples of AT computers. The time periods for these computers are from 1982 - 1995. These computers can run any type of soft wares including text based as well as graphical base and processor speed of these computers is up to 233 MHz.

PS/2 (Personal System / 2) Computer
IBM started manufacturing next model of computer since 1990. This model is called PS? 2 computers. Most of the computers manufactured after 1990 including laptop, belongs to this model. These computers are refinement of AT computers. These computers can run almost all software & programs.

4. On the Basis of Brand

Computer has two world wide brands:

IBM PC
The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. IBM PC is the largest computer manufacturing company establishing USA. The computer manufactures by IBM PC or branded computer. Personal Computer (PC) is the most important type of micro computer system. The micro computer manufactures by IBM Company are called IBM PC. These computers are reliable, durable and have better quality but they are costly.

Apple/Macintosh Computer
All the computers manufacture by apple cooperation, a leading computers manufacturing computer of USA are known as apple/Macintosh computers. The Apple series of micro computers was developed by Steve Wozniak & Steve Jobs in 1976. This used 8-bit microprocessor chips. These computers use their own software and hardware. They are totally different than that of IBM computers, In terms of both hardware and software. For e.g. software developed for apple computer can't run or IBM computers and vice-versa. Similarly, floppy disk formatting in IBM computer can't be recognized by apple Macintosh computer and vice-versa. It is popularly used in desktop publishing (DTP) houses as they provide better quality of graphic output.

Types of Computer

2. On the Basis of Size

Super Computer
Multi-user, multiprocessor large computer of very high efficiency and storing capacity is called super computer. Super computer is able to solve very difficult and complex problem within a Nano seconds. Its world length is 64 bits. PARAM Series, ANURAG, CRAY, XMP/14, CDC-205, etc. are some examples.

Application

• Used to forecast the weather and global climates
• Used in military research & defense system.
• In automobile, Aircraft & space craft design.
• In encrypting & decoding sensitive intelligence information.
• Study of DNA structure and gene engineering.
• Digital Film rendering.

Mainframe Computer
Mainframe computer is also very powerful multi-user computer used in large business, organizations, examination department of industries and defense to process data of complex nature. It can response several hundred request very quickly. It uses several CPU for data processing. More than 100 users can use at time because it works on time sharing mode. Its word length is 48 bits to 64 bits. IBM S/390, IBM S/709, ICL 39 are some examples.

Application

• Government & Civilian
• Credit card processing
• Bank Account Management
•  Marketing
• Air Traffic Control system
• Industrial Design

Minicomputer
Minicomputers are larger and more powerful than most microcomputer but are smaller and less powerful than most large mainframe computer systems. It is also multi-user computer and supports more than dozens of people at a time. It is costlier than microcomputer. It is also used in university, large business organizations to process complex data. It is also used in scientific research, instrumentation system, engineering analysis and industrial process monitoring and control. PDP-11, VAX, etc. are some examples.

Micro computer
Microcomputers are used in daily purpose. It uses microprocessors. Now a day mostly used computer are microcomputers which we called Home PC or Personal Computer (PC) because it is a single user computer. It supports many high level languages, multimedia, graphics, 3d graphics & games. It is popular among student, professionals due to small size, low cost & low maintenance cost & easy in operation. The internet is popular due to PC & it is available for all income groups. IBM PCs, Apple Mac, IBM PS/2, etc. are some example of microcomputer.
 

Types of Computer

1. On the basis of Work

Analog Computer

An analog computer is one that measures physical values such as temperature, pressure. For example a service station gasoline pump contains an analog processor and analog device that converts fuel flow measurement into quantity and price values. The term analog computer is derived from a Greek word analog. Speedometer in cars is another example of an analog computer.

Digital Computer

A digital computer is one that directly counts numbers or digits that present number letter or other special symbol. Digital computer does not measure the distance or does not measure how many liter of petrol are taken or what is the pressure of compression etc. Digital Computers are the most used computer for report, documentations, billing & other graphical work. The entire PC used today on different fields is the microcomputers.

Hybrid Computers

There are the computers, which work on digital as well as analog computer type. Accuracy of hybrid computer are combined on these computers mad the hybrid computer. These are used on Intensive Care Unit of Hospital, jet planes & other data analyst terminal. Hybrid computer transfer the data from analog to digital and digital to analog & vice versa.

Comparison between Analog, Digital & Hybrid Computer

Analog Computer

• A computer that uses analog signal to display information is called analog computer.
• Information in continuous form and displayed in the form of curves. It is used to measure continuous physical quantity like as current flow, temperatures, blood pressure, heartbeats.
• Fast
• Less Accurate
• Special Purpose
• Noisy
• Not use for programming
• No memory storage

Digital Computer

• Computers that use binary digits to display discrete information is called digital computer.
• Information is in discrete form. It displays information in the form of text, graphics and pictures.
• Slow
• Accurate
• General Purpose
• Less Noisy
• Use for Programming
• Storage Memory

Hybrid Computer

• A computer that is able to understand binary as well as analog signal to display information is called Hybrid computers.
• Information depends on operating mode of computers. It can display information in discrete and continuous form because it’s one part is dedicated for digital processing and next part is for analog processing.
• Intermediate in speed
• Intermediate Special Purpose
• Noise depend on computer
• Programming depend on computer
• Memory depend on computer

Generation of Computer

Fifth Generation (Present and Beyond) Artificial Intelligence

Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.

Some of its features are:

• Computers based on artificial intelligence
• Used superconductors
• Used in speech recognition
• Used in intelligent robots
• Computers use extensive parallel processing, multiple pipelines, multiple processors etc.
• Massive parallel machines and extensively distributed system connected by communication networks fall in this category.
• Superscalar processors, Vector processors, SIMD processors, 32 bit micro controllers and embedded processors, Digital Signal Processors (DSP) etc.
• Memory chips up far beyond the present capacity.
• Development of powerful programming languages like Object oriented languages of  presents for suitable programming.
• Storage technology advanced – large main memory and disk storage available
• Got hot pluggable features which enable a failed component to be replaced with a new one without the need to shutdown the system, allowing the uptime of the system to be very high.
• The recent development in the application of internet is the Grid technology which is still in its upcoming stage.
• Quantum mechanism and nanotechnology will radically change the phase of computers.

Generation of Computer

Third Generation (1964-1971) Integrated Circuits

The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.

Some of its features are :

• ICs were used
• Small Scale Integration and Medium Scale Integration technology were implemented in CPU.
• Keyboards and monitors as the I/O devices instead of punched card & Printouts.
• Smaller & better performance
• Comparatively lesser cost
• Faster processors
• In the beginning magnetic core memories were used. Later they were replaced by semiconductor memories (RAM & ROM)
• Introduced microprogramming
• Microprogramming, parallel processing (pipelining, multiprocessor system etc), multiprogramming, multi-user system (time shared system) etc were introduced.
• Operating system software were introduced (efficient sharing of a computer system by several user programs)
• Cache and virtual memories were introduced (Cache memory makes the main memory appear faster than it really is. Virtual memory makes it appear larger)
• Database management, multi-user application, online systems like closed loop process control, airline reservation, interactive query systems, automatic industrial control etc emerged during this period.
• High level languages were standardized by ANSI eg. ANSI FORTRAN, ANSI COBOL etc

Fourth Generation (1971-Present) Microprocessors
The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. VLSI & ULSI is the major achievement of fourth generation of computer. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer from the central processing unit and memory to input/output controls on a single chip.

In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors.

As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet.

Some of its Features are:

• Microprocessors were introduced as CPU– Complete processors and large section of main memory could be implemented in a single chip
• Tens of thousands of transistors can be placed in a single chip (VLSI design implemented)
• CRT screen, laser & ink jet printers, scanners etc were developed.
• Semiconductor memory chips were used as the main memory.
• Secondary memory was composed of hard disks – Floppy disks & magnetic tapes were used for backup memory
• Parallelism, pipelining cache memory and virtual memory were applied in a better way
• LAN and WANS were developed (where desktop work stations interconnected)
• Introduced C language and Unix OS
• Introduced Graphical User Interface
• Less power consumption
• High performance, lower cost and very compact
• Much increase in the speed of operation

Generation of Computer

Each generation of computer is characterized by a major technological development that fundamentally changed the way computers operate, resulting in increasingly smaller, cheaper, more powerful and more efficient and reliable devices.

First Generation (1940-1956) Vacuum Tubes

First Generation of computer was introduced by the Charles Babbage. These computers used vacuum tubes as the main component & also used for memory. If any problem arises in the computer, it is very difficult to debug as the computer uses more than 20,000 thousand vacuum tubes in a single computer. They were often enormous in size, taking up entire rooms. These computers are so expensive that only country has the computer.

Some of its features are :

• Basic arithmetic operations took few milliseconds.
• Bulky in size, takes entire room.
• Single vacuum tube can store only 4Kb.
• Consume more power with limited performance.
• High cost .
• Uses machine level language for execution, the lowest-level programming language understood by computers.
• They could only solve one problem at a time.
• Mercury delay line memories and Electrostatic memories were used.
• Punched cards and paper tape were invented to feed programs and data and to get results.
• Mainly used for scientific computations. 
• UNIVAC and ENIAC computers are examples of first-generation computing devices.

Second Generation (1956-1963) Transistors
Development of the transistors was the major change of second generation of computer. Single Transistors replaced 2000vacuum tubes. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors.

Some of its features are:

• Transistors were used in place of vacuum tubes
• Small in size
• Lesser power consumption and better performance
• Lower cost
• Magnetic ferrite core memories were used as main memory which is a random-access nonvolatile memory
• Magnetic tapes and magnetic disks were used as secondary memory
• Second-generation computers moved from cryptic binary machine language to assembly languages, which allowed programmers to specify instructions in words.
• High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN.
• First computers that stored their instructions in their memory.

Overview of Computer

A computer is a electronic programmable machine which can perform a specific set of instructions in a well-defined manner & also executes a prerecorded list of instructions which we know as program. It can be programmed to carry out numerous logical & arithmetic operations. Computer takes the data from input devices, then it stores, process & outputs the resulted data through the output devices. The first electronic digital computers were developed between 1940 and 1945. Originally they were the huge machines, consuming as much power as several hundred modern personal computers & required teams of people to operate. Compared to those early machines, today's computers are amazing. Not only are they thousands of times faster, they can fit on your desk, in your lap, or even in your pocket.

A computer system has three main components: hardware, software, and people. Hardware refers to the parts of a computer that you can see and touch, including the case and everything inside it. Computers work through an interaction of hardware and software. The most important piece of hardware is a tiny rectangular chip inside your computer called the central processing unit (CPU), which we also generally know as the microprocessor. It is the "brain" of your computer. This part of computer translates instructions and performs calculations. Hardware items are such as your monitor, keyboard, mouse, printer, and other items are often called hardware devices.

 Software refers to the instructions, or programs, that tell the hardware what to do. A word processing program that you can use to write letters on your computer is a type of software. The operating system (OS) is software that manages your computer and the devices connected to it. Two well-known operating systems are Windows and Macintosh operating system. Some other examples of OS are Ubantu, Linux, etc. Most of the people use the Windows operating system.

People, however, are the most important component of a computer system that uses the power of computer for different purposes. In today’s world, we can see computer in every field like in restaurant, colleges, schools, government offices, business organization, & so on.