Hardware - 1: Components of a Computer

1. Hardware - 1:Components of a Computer

2. Objectives The objectives of this session (three lectures) are to: • define the nature of data and information • describe how computers represent data • define the principal physical components of a computer system. • describe in broad terms how each component works. • describe the operating/performance characteristics of each component. • show how these components inter-relate. • look at trends in current technology • give you a sufficient understanding of the technology to underpin your understanding of Information Systems

3. PC Advertisement THE STUDENT SPECIAL - Dell Inspiron 530 • Intel® Core™ 2 Duo E4400 Processor (2.0GHz,800MHz,2MB cache) • 1.0 GB 533Mhz RAM (2x512) • 250GB Serial ATA Hard Drive • 19” Flat Panel Monitor (19.0” v.i.s) • 256MB nVidia™ GeForce 8600GT graphics card • 16x DVD/ +/- RW Combo Drive • SoundBlaster Compatible On-Board Sound • Dell Stereo Speakers • 1GB USB Memory Key • Microsoft Windows XP Professional SP2 • Microsoft Works 7.0

4. What is Data? • Definitions: • A series of non-random symbols, number, values or words. • A series of facts obtained by observation or research • A collection of non-random facts • The record of an event or fact • Examples: • today’s date; • measurements taken on a production line; • records of business transactions.

5. What is Information? • Definitions: • Data that has been processed so that they are meaningful. • Data that has been processed for a purpose. • Data that has been interpreted and understood by the recipient. • Examples: • A bank statement; • A sales forecast; • A telephone directory. • Information Warfare

6. Components of a PC Hardware System The computer does something to it Input Processing Output You get something out You put something in Storage DATA INFORMATION The computer may store it for a while

7. Word Count on a Word Document The computer does something to it Word Document + Program Instructions Counting Number of Words Pop-up window with Word Count DATA INFORMATION Store Document Running Total Program Instructions The computer may store it for a while

8. Components of a PC Hardware System Central Processing Unit (CPU) • Output Devices • Printers • Video display • Input Devices • Keyboard • Mouse Buses • Secondary Storage • Magnetic disk • Optical disk Communication Devices Primary Storage

9. How Computers Represent Data • Bit • Byte • Size is normally expressed in Bytes • Standard measures are: • 1,024 bytes = 1 kilobyte (KB) (1,024 = 2 x2 x 2 x2 x 2 x 2 x 2 x2 x 2 x2) • 1,024 KB = 1 Megabyte (MB) • 1,024 MB = 1 Gigabyte (GB) • 1,024 GB = 1 Terabyte (TB) • 1,024 TB = 1 Petabyte (PB) • 1,024 PB = 1 Exabyte (EB) • 1 EB is approximately 1,000,000,000,000,000,000 bytes. • Today PC memory is measured in Megabytes, PC disk in Gigabytes and mainframe disks in Terabytes.

10. Some Sizes

11. However... • When talking of: • Processors (CPU) and • Communications use bit. • A 56.8 Kbps modem means 56,800 bits per second = KB • Processors are often described as 8, 16, 32 or 64 bit.

12. The Central Processing Unit (CPU) The CPU Control Unit ALU Input Devices Output Devices Registers Instruction Set Primary Storage Secondary Storage

13. The Central Processing Unit (CPU) • Core components • Control Unit • Arithmetic-Logic Unit • Registers • Instruction Set • Clock • Primary Storage • Optional • Cache

14. The CPU (continued) • Control Unit • Access program instructions • Decode (interpret) instructions • Control flow of data throughout system • Data flows through paths called buses • Arithmetic-Logic Unit • Perform computations on data • Perform comparisons on data • Registers • High speed storage areas • Hold data and instructions

15. The CPU (continued) • Instruction Set • Pre-programmed functions • Clock • Sequences events • Primary Storage (Main Memory) • Stores instructions from programs • Stores data to be processed • Cache Memory (optional) • Overheats – Heat sync • Iitac

16. Speed of a Chip • Cycle Speed • Clock speed – beat frequency of the clock (in MHz) determines how many times per second the processor performs operations. • Intel® Core™ 2 Duo E4400 Processor (2.0GHz,800MHz,2MB cache) – 2 billion cycles per second • Word Length • No. of bits that can be processed at any one time. • Pentium D processes 64 bits of data in one machine cycle.

17. Speed of a Chip • Data Bus Width • The physical paths down which the data and instructions travel. • The wider the bus the more data can be moved – faster! • Bus bandwidth: The product of the width of its bus (in bits) times the frequency at which the bus transfers data (MHz). • Line width • Distance between transistors (the smaller this is the more transistors can fit on the chip)

18. The Microprocessor The Intel Pentium D is one example It is the latest generation of a series that started with 8086 c. 1978. Silicon on a ceramic base Approximately 100 pins to link to remainder of computer Contains the basic processing functions Uses 64 bit registers Intel Compatibles Advanced Micro Devices (AMD) Cyrix Corporation

19. Examples of Microprocessors

20. Getting More Performance • Instruction sets • Complex Instruction Set Computer or CISC. • Intel x86, Pentium • Reduced Instruction Set Computers(RISC) • Power PC • Very Long Instruction Word (VLIW) • Intel Itanium • Explicitly Parallel Instruction Computing • Intel Pentium 4

21. Multiple Processor Machines Program Program TASK 1 RESULT CPU CPU CPU CPU TASK 1 TASK 2 TASK 3 RESULT Program TASK 2 RESULT CPU SEQUENTIAL PARALLEL MASSIVE PARALLEL COMPUTERS CAN HAVE THOUSANDS OF CPUs TO ATTACK LARGE COMPUTING PROBLEMS

22. Other Chips Specialised chips are often on daughterboards CPUs alone do not run a working computer • Specialised • chips include: • Video memory • Graphics processing • Encryption • Language compilers • Floating point • arithmetic Other chips are needed. Some contain startup information, instructions Standard chips are found on the motherboard

23. PC 1991

24. PC 2007

25. PC Advertisement THE STUDENT SPECIAL - Dell Inspiron 530 • Intel® Core™ 2 Duo E4400 Processor (2.0GHz,800MHz,2MB cache) • 1.0 GB 533Mhz RAM (2x512) • 250GB Serial ATA Hard Drive • 19” Flat Panel Monitor (19.0” v.i.s) • 256MB nVidia™ GeForce 8600GT graphics card • 16x DVD/ +/- RW Combo Drive • SoundBlaster Compatible On-Board Sound • Dell Stereo Speakers • 1GB USB Memory Key • Microsoft Windows XP Professional SP2 • Microsoft Works 7.0

26. Primary Storage • Stores data and program statements for the CPU • Data that have been input before being transferred to the ALU. • Data and results during intermediate stages of processing. • Data after processing until being transferred to an output device. • Program statements/instructions received from input devices and secondary storage.

27. RAM (random access memory) • Where the CPU stores the instructions and data it is processing. • Size (1.0GB for multimedia) • Speed • Address • Memory is an array of silicon based binary switches • Volatile • Virtual memory

28. Cache Memory • Temporary storage for frequently used blocks of programmes. • High speed. • Primary (Level 1 cache) – located in the processor. • Secondary (Level 2 cache) – located on the motherboard.

29. ROM (read only memory) • Portion of Primary Storage that cannot be changed or erased. • Nonvolatile • Booting up • BIOS • POST

30. Storage Speeds Level 1 Cache Level 2 Cache Cheap Expensive Large Amount Small Amount

31. PC Advertisement THE STUDENT SPECIAL - Dell Inspiron 530 • Intel® Core™ 2 Duo E4400 Processor (2.0GHz,800MHz,2MB cache) • 1.0 GB 533Mhz RAM (2x512) • 250GB Serial ATA Hard Drive • 19” Flat Panel Monitor (19.0” v.i.s) • 256MB nVidia™ GeForce 8600GT graphics card • 16x DVD/ +/- RW Combo Drive • SoundBlaster Compatible On-Board Sound • Dell Stereo Speakers • 1GB USB Memory Key • Microsoft Windows XP Professional SP2 • Microsoft Works 7.0

32. TO DO!! What is Grid Computing, how does it work, where is it used?

33. Summary of Key Points • Computers comprise input, output, storage and processing devices. • Computers are made up of many components of which the most important is the Central Processing Unit. • Processor performance depends on: • Register size; • Clock speed; • Bus size; • Line width. • Currently processors are mostly 64 bit. • There is a steady trend toward multiprocessing machines.