Chapter Two: Computer Evolution and Performance

1. Chapter Two: Computer Evolution and Performance Prepared by: Dr. Bahjat Qazzaz

2. Introduction • Processor speed------increase • Component size------decrease • Memory capacity------increase • I/O capacity and speed-------Increased • Cost--------------Decreased

3. Introduction •  Processor speed can be attributed to تعزى الى • (In past) Decreasing and shrinking the processor components size • (Recently) Processor organization (true gain) using pipelining, parallel execution, and speculative execution techniques

4. Introduction • Critical issue in computer system-----Balancing the performance between computer components: • processor is faster than access time of memory • To solve this problem • Caches • Wider data paths • More intelligent memory chips

5. Computers Generations • 1943-1946 ENIAC • Ballistic Research Laboratory • 30 Tons • 18000 vacuum tubes • 1500 square feet • 5000 additions

6. Computers Generations • 1945 von Neumann machine • EDVAC • Entering data to ENIAC was tedious • Solution: stored-program concept program and data are stored in a memory Then, they are fetched

7. Computers Generations • 1946-1952 IAS (Institute for Advanced Research) • IAS a new stored-program computer by Von.. • Finished in 1952 • IAS becomes the prototype of all subsequent computers

8. Main Memory Arithmetic Logic Unit I/O equip-ment Program Control Unit Structure of IAS Computer Computers Generations • IAS architecture consists of • Memory • ALU • CU • I/O equipment

9. Computers Generations • The ALU and CU contain storage locations called registers: • Memory Buffer Register (MBR) • Memory Address Register (MAR) • Instruction Register (IR)--- 8-bit opcode • Instruction Buffer Register (IBR)--- the right-hand instruction • Program Counter (PC) • Accumulator (AC) and multiplier quotient (MQ)---holds operands and results of ALU operations temporarily

10. Arithmetic-logic unit (ALU) Input- Output Equipment AC MQ Arithmetic-logic circuit MBR Main Memory IBR PC IR MAR Control circuits control signals address Program control unit (CU)

11. Computers Generations • IAS operates by repetitively performing an instruction cycle, each instruction consists of two subcycle: • Fetch cycle: an instruction is taken from memory, then to MBR, down to the IBR, IR, and MAR. Or it can be taken from IBR. The opcode is loaded to IR, and the address portion is loaded into MAR. • Execute cycle: control circuitry interprets the opcode and execute the instruction by sending out appropriate control signals to cause data to be moved or an operation to be performed by the ALU.

12. 0 1 39 Number Word in IAS Computer Computers Generations • Characteristics of IAS architecture • 1000 storage locations (called words) • each word is 40 bit length • data and instruction are stored in the word • Thus, data and instruction are in binary form • A number is represented by 1-sign bit and 39-bit value

13. Left instruction Right instruction 0 8 20 28 39 Opcode Address Opcode Address Instruction Word in IAS Computer Computers Generations • Characteristics of IAS architecture • A word can include two 20-bit instructions

14. Computers Generations • IAS has 21 instruction grouped as follow: • Data transfer • Unconditional branch • Conditional branch • Arithmetic • Address modify

15. Computers Generations

16. Computers Generations Commercial computers 1950 witnessed the birth of computer industry, Sperry and IBM UNIVAC I (Universal Automatic Computer), was the first successful commercial computer, for calculations. UNIVAC II, had greater memory capacity and higher performance.

17. Computers Generations • Upward compatible: Programs written for older machines can be executed on the new machine. • UNIVAC 1103 (1100 series) and its successors, for scientific applications. • 1953, IBM delivered its first electronic stored-program computer (the 701) for scientific applications, and the 702 for business application (had some hardware features suited business applications.

18. Computers Generations • The Second generation: Transistors • In this generation, transistor replaced the vacuum tube and used to construct computers. • Transistors (made form silicon) are smaller, cheaper, and dissipate (emits) less heat than vacuum tube. • Transistor was invented in 1947 at Bell Labs, and used late 1950. • NCR and RCA (small transistor machines), then IBM used this technology (IBM with its 7000 series).

19. Computers Generations

20. Computers Generations • Complex ALU and CU, High-level programming languages, and system software were born in this generation. • DEC (Digital Equipment Corporation) appeared and was founded in 1957, started the production of mini computer, it became prominent in the third generation.

21. Computers Generations • IBM 7094 • Increased performance, increased capacity, and lower cost • Memory increase from 2K to 32 Kword • Memory cycle time , the time needed to access a word from the memory, has fallen from 30µ to 1.4µ • Number of opcodes grew from 24 to 185 • Processor speed increased because of transistors and more complex circuitry. Example, 7094 used backup register.

22. Computers Generations • Data channel (this does not exist in IAS): is an independent I/O module with its own processor and instruction set. • Multiplexor (also, this does not exist in IAS): schedules access from the CPU and datachannel.

23. Computers Generations

24. Computers Generations • The third generation: Integrated circuit • Before, discrete components (transistors, capacitor, and resistors) were manufactured separately, packaged in their own containers, and soldered (wired) together onto circuit boards which were then installed in computers. This process (from transistors to circuit board) was expensive and difficult. • In third generation integrated circuit were used • Also, two important members IBM System/360 & DEC PDP-8

25. Computers Generations • Microelectronics: • Means small electronics • Trend toward size reduction of digital electronic circuits • Digital computer consists of two major things

26. Computers Generations • Gates: a gate is a device that implements a simple Boolean or logical function

27. Computers Generations • Memory cells: is a device that can store one bit of data

28. Computers Generations • Interconnections: By interconnecting large number of the above devices we can construct a computer • Data storage---by memory cells • Data processing---by gates • Data movement---through gates and paths bwn components • Control---paths carry signals from gates to access memory for example R/W signals.

29. Computers Generations • The idea is to fabricate the entire circuit from silicon rather than assemble discrete components made from separate pieces of silicon into the same circuit. • Many transistors can be produced at the same time on a single wafer of silicon.

30. Computers Generations • Key concept of integrated circuit • A thin wafer of silicon is divided into a matrix of small areas • Identical circuit is fabricated in each area • The wafer is then broken up into chips • Each chip may include gates, memory cells, and I/O attachment points • The chip is packaged in housing that protects it and provides pins for attachment to devices beyond the chip. • A number of these packaged can then be interconnected on a printed circuit board to produce larger and more complex circuit.

31. Computers Generations • SSI (small-scale integration): small number of gates or memory cells is packaged together.

32. Computers Generations • Characteristics of computer became as follow: • Cost of computer logic and memory circuitry has fallen • Operating speed increase as a result of shortening electrical path. • Computer becomes smaller; it can be places in different environment. • Reduction in power and cooling requirements • The interconnection on the integrated circuit is much more reliable and less interchip connection.

33. Computers Generations • IBM System 360 family • Bad news for IBM customers because it is not compatible • It uses integrated circuit • Its architecture remains to this day the architecture of IBM’s mainframe computers. • The 360 family models are compatible.

34. Computers Generations • Family characteristics • Similar or identical instruction set---so a program execute on one machine can execute on any other • Similar or identical operating system---but, additional features might have been added to the higher-end members • Increasing speed---increasing the rate of instruction execution • Increasing number of I/O ports---more ports are added • Increasing memory size---size is increasing as we go up • Decreasing cost---cost is reduced

35. Computers Generations • With regard to the speed: • Because of more complex circuitry in ALU allowing parallelism • Because of increasing the width of data path bwn CPU and Memory

36. Computers Generations • DEC PDP-8 • It produced a small computer with cheaper prices ($16000). • The established the concept of minicomputers and produced 50000 machine, all reserved by IBM • It became number two after IBM as computer manufacturer.

37. Console controller CPU Main memory I/O module I/O module Omnibus Computers Generations • DEC used the BUS STRUCTURE called the OMNIBUS consists of 96 separate signal paths to carry signals, address, and data signals

38. Computers Generations • Later Generation • Large-scale Integration: more than 1000components can be placed on a single integrated chip. • Very-large scale integration (VLSI), achieve more than 10000 components • Current VLSI achieves more than 100000 components.

39. Computers Generations • Semiconductor Memory • Integrated circuits were used for the construction of • CPU (ALU & CU) & • For the construction of the memories.

40. Computers Generations • Microprocessors • As time went on, more and more elements were placed on each chip, so that • Fewer and fewer chips were needed to construct a single computer processor • In 1971, Microprocessor was born when Intel developed the first chip which had all of the CPU (4004, it is a 4-bit processor which adds two-4 bit numbers) components on a single chip.

41. Computers Generations • The data bus width marked the or became the measure for the development, also • The number of bits in the accumulator • In 1972, Intel introduced 8008 processor. It was the first 8-bit microprocessor

42. Computers Generations • In 1974, Intel introduced the major event Intel 8080, • it is the first general-purpose microcomputer. • It is faster than 8008, • had a richer instruction set, • and has larger addressing capacity. • It was 8-bit processor.

43. Computers Generations • End of 1970s, the 8086 was the first general-purpose 16-bit microprocessor. • 1981, Bell Labs & Hewlett-Packard developed 32-bit single-chip microprocessor

44. Computers Generations • 1985, introduced its own 32-bit microprocessor the 80386. • 1989, 80486 • 1993 Pentium • 1995 Pentium pro • 1997 Pentium II • 1999 Pentium III • 2000 Pentium 4 • 2001 Itanium • 2002 Itanium 2

45. Computers Generations • To summarize • Vacuum tube - 1946-1957 • Transistor - 1958-1964 • Small scale integration - 1965 on • Up to 100 devices on a chip • Medium scale integration - to 1971 • 100-3,000 devices on a chip • Large scale integration - 1971-1977 • 3,000 - 100,000 devices on a chip • Very large scale integration - 1978 -1991 • 100,000 - 100,000,000 devices on a chip • Ultra large scale integration – 1991 - • Over 100,000,000 devices on a chip

46. Computers Generations • Moors’ Law (Intel 1965) • Increased density of components on chip • Number of transistors on a chip will double every year • Since 1970’s development has slowed a little • Number of transistors doubles every 18 months • Cost of a chip has remained almost unchanged • Higher packing density means shorter electrical paths, giving higher performance • Smaller size gives increased flexibility • Reduced power and cooling requirements • Fewer interconnections increases reliability

47. Computers Generations

48. Computers Generations • Design for performance • The performance and capacity of computers have increased and their cost continued to drop dramatically. • Inside the computer you find microprocessor, memory, chips, and 100s of millions of transistors (Toilet paper is more expensive).

49. Computers Generations • However, applications became resources (CPU power, memory capacity, bandwidth) hungry. Such applications include: • Image processing • Speech recognition • Multimedia authoring • Voice and video annotation of files • Simulation modeling

50. Computers Generations • For this reasons, workstations and servers present the required power. • These machines have the same building block of the IAS architecture • Consequently, in the next chapters we focus on • Explaining the fundamental functionality in each area under consideration • Exploring the techniques required to achieve maximum performance.