Lecture 2: Fundamentals of Computer Design - PowerPoint PPT Presentation

Loading...

PPT – Lecture 2: Fundamentals of Computer Design PowerPoint presentation | free to download - id: 7dadbd-NjdkM



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Lecture 2: Fundamentals of Computer Design

Description:

... Fundamentals of ... Instruction Set Architecture Trends Dependability Performance ... Primary energy consumption within a microprocessor is for ... – PowerPoint PPT presentation

Number of Views:83
Avg rating:3.0/5.0
Slides: 95
Provided by: educ5490
Learn more at: http://list.zju.edu.cn
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Lecture 2: Fundamentals of Computer Design


1
Lecture 2 Fundamentalsof Computer Design
  • Kai Bu
  • kaibu_at_zju.edu.cn
  • http//list.zju.edu.cn/kaibu/comparch

2
Chapter 1
3
  • Transition from single processor to multiple
    processors
  • Quantitative approach empirical observations (of
    programs, experimentations, simulation) as its
    tools

4
Outline
  • Classes of computers
  • Parallelism
  • Instruction Set Architecture
  • Trends
  • Dependability
  • Performance Measurement

5
Outline
  • Classes of computers
  • Parallelism
  • Instruction Set Architecture
  • Trends
  • Dependability
  • Performance Measurement

6
5 Classes of Computers
7
PMD Personal Mobile Device
  • Wireless devices with multimedia user interfaces
  • cell phones, tablet computers, etc.
  • a few hundred dollars

8
PMD Characteristics
  • Cost effectiveness
  • less expensive packaging
  • absence of fan for cooling
  • Responsiveness Predictability
  • real-time performance a maximum execution time
    for each app segment
  • soft real-time average time constraint
    tolerate occasionally missed time constraint on
    an event.
  • Memory efficiency
  • optimize code size
  • Energy efficiency
  • battery power, heat dissipation

9
Desktop Computing
  • Largest market share
  • low-end netbooks x00
  • high-end workstations x000

10
Desktop Characteristics
  • Price-Performance
  • combination of performance and price
  • compute performance
  • graphics performance
  • The most important to customers,
  • and hence to computer designers

11
Servers
  • Provide large-scale and reliable file and
    computing services (to desktops)
  • Constitute the backbone of large-scale enterprise
    computing

12
Servers Characteristics
  • Availability
  • against server failure
  • Scalability
  • in response to increasing demand with scaling up
    computing capacity, memory, storage, and I/O
    bandwidth
  • Efficient throughput
  • toward more requests handled in a unit time

13
Why Server Availability
14
Clusters/WSCs
  • Warehouse-Scale Computers
  • collections of desktop computers or servers
  • connected by local area networks
  • to act as a single larger computer
  • Characteristics
  • price-performance, power, availability

15
Embedded Computers
  • hide everywhere

16
Embedded vs Non-embedded
  • Dividing line
  • the ability to run third-party software
  • Embedded computers primary goal
  • meet the performance need at a minimum price
  • rather than achieve higher performance at a
    higher price

17
Outline
  • Classes of computers
  • Parallelism
  • Instruction Set Architecture
  • Trends
  • Dependability
  • Performance Measurement

18
Application Parallelism
  • DLP Data-Level Parallelism
  • many data items being operated on at the same
    time
  • TLP Task-Level Parallelism
  • tasks of work created to be operate
    independently and largely in parallel

19
Hardware Parallelism
  • Computer hardware exploits two kinds of
    application parallelism in four major ways
  • Instruction-Level Parallelism
  • Vector Architectures and GPUs
  • Thread-Level Parallelism
  • Request-Level Parallelism

20
Hardware Parallelism
  • Instruction-Level Parallelism
  • exploits data-level parallelism
  • at modest levels pipelining
  • at medium levels speculative exec

21
Hardware Parallelism
  • Vector Architectures
  • GPUs (Graphic Process Units)
  • exploit data-level parallelism
  • apply a single instruction to a collection of
    data in parallel

22
Hardware Parallelism
  • Thread-Level Parallelism
  • exploits either DLP or TLP
  • in a tightly coupled hardware model
  • that allows for interaction among parallel
    threads

23
Hardware Parallelism
  • Request-Level Parallelism
  • exploits parallelism among largely decoupled
    tasks specified by the programmer or the OS

24
Classes of Parallel Architectures
  • by Michael Flynn
  • according to the parallelism
  • in the instruction and data
  • streams called for by the
  • instructions at the most
  • constrained component of
  • the multiprocessor
  • SISD, SIMD, MISD, MIMD

25
SISD
  • Single instruction stream, single data stream
    uniprocessor
  • Can exploit instruction-level parallelism

26
SIMD
  • Single instruction stream, multiple data stream
  • The same instruction is executed by multiple
    processors using different data streams.
  • Exploits data-level parallelism
  • Data memory for each processor
  • whereas a single instruction memory and control
    processor.

27
MISD
  • Multiple instruction streams, single data stream
  • No commercial multiprocessor of this type yet

28
MIMD
  • Multiple instruction streams, multiple data
    streams
  • Each processor fetches its own instructions and
    operates on its own data.
  • Exploits task-level parallelism

29
Outline
  • Classes of computers
  • Parallelism
  • Instruction Set Architecture
  • Trends
  • Dependability
  • Performance Measurement

30
Instruction Set Architecture
  • ISA
  • actual programmer-visible instruction set
  • the boundary between software and hardware
  • 7 major dimensions

31
ISA Class
  • Most are general-purpose register architectures
    with operands of either registers or memory
    locations
  • Two popular versions
  • register-memory ISA e.g., 80x86
  • many instructions can access memory
  • load-store ISA e.g., ARM, MIPS
  • only load or store instructions can access
    memory

32
ISA Memory Addressing
  • Byte addressing
  • Aligned address
  • object width s bytes
  • address A
  • aligned if A mod s 0

33
Each misaligned object requires two memory
accesses
34
ISA Addressing Modes
  • Specify the address of a memory object
  • Register, Immediate, Displacement

35
ISA Types and Sizes of OPerands
Type Size in bits
ASCII character 8
Unicode character Half word 16
Integer word 32
Double word Long integer 64
IEEE 754 floating point single precision 32
IEEE 754 floating point double precision 64
Floating point extended double precision 80
36
MIPS64 Operations
  • Data transfer

37
MIPS64 Operations
  • Arithmetic Logical

38
MIPS64 Operations
  • Control

39
MIPS64 Operations
  • Floating point

40
ISA Control Flow Instructions
  • Types
  • conditional branches
  • unconditional jumps
  • procedure calls
  • returns
  • Branch address add an address field to PC
    (program counter)

41
ISA Encoding an ISA
  • Fixed length ARM, MIPS 32 bits
  • Variable length 80x86 118 bytes

http//en.wikipedia.org/wiki/MIPS_architecture

Start with a 6-bit opcode. R-type three
registers, a shift amount field, and a function
field I-type two registers,a 16-bit
immediate value J-type a 26-bit jump target.
42
Computer Architecture
ISA Organization Hardware
  • actual programmer
  • visible instruction set
  • boundary between sw
  • and hw

high-level aspects of computer design memory
system, memory interconnect, design of internal
processor or CPU
computer specifics logic design, packaging tech
43
Outline
  • Classes of computers
  • Parallelism
  • Instruction Set Architecture
  • Trends
  • Dependability
  • Performance Measurement

44
Five CriticalImplementation Technologies
  • Integrated circuit logic technology
  • Semiconductor DRAM
  • Semiconductor flash
  • Magnetic disk technology
  • Network technology

45
Integrated circuit logic technology
  • Moores Law a growth rate in
  • transistor count
    on
  • a chip of about
  • 40 to 55
  • per year
  • doubles every
  • 18 to 24 months

46
Semiconductor DRAM
  • Capacity per DRAM chip doubles roughly every 2 or
    3 years

47
Semiconductor Flash
  • Electronically erasable programmable read-only
    memory
  • Capacity per Flash chip doubles roughly every two
    years
  • In 2011, 15 to 20 times cheaper per bit than DRAM

48
Magnetic Disk Technology
  • Since 2004, density doubles every three years
  • 15 to 20 times cheaper per bit than Flash
  • 300 to 500 times cheaper per bit than DRAM
  • For server and warehouse scale storage

49
Network Technology
  • Switches
  • Transmission systems

50
Performance Trends
  • Bandwidth/Throughput
  • the total amount of work done in a given time
  • Latency/Response Time
  • the time between the start and the completion of
    an event

51
Bandwidth over Latency
52
Trends in Power and Energy
  • Power Energy per unit time
  • 1 watt 1 joule per second
  • energy to execute a workload
  • avg power x execution time
  • Three primary concerns
  • the max power for a processor
  • sustained power consumption
  • energy and energy efficiency

53
Trends in Power and Energy
  • Sustained power consumption
  • Metric TDP
  • Thermal Design Power
  • determines cooling requirement
  • Heat management
  • 1. reduce clock rate and hence power as the
    thermal temperature approaches the junction
    temperature limit
  • 2. if 1 is not working, power down the chip.

54
Trends in Power and Energy
  • Energy and Energy Efficiency
  • energy to execute a workload
  • avg power x execution time
  • Example
  • processor A with 20 higher avg power
    consumption than processor B
  • but A executes the task with 70 of the time by
    B
  • A or B is more efficient?

55
Trends in Power and Energy
  • Example
  • processor A with 20 higher avg power
    consumption than processor B
  • but A executes the task with 70 of the time by
    B
  • A or B is more efficient?
  • EnergyConsumptionA
  • 1.2 x 0.7 x EnergyConsumptionB
  • 0.84 x EnergyConsumptionB

56
Trends in Power and Energy
  • Primary energy consumption within a
    microprocessor is for switching transistors
    dynamic energy
  • logic transistion 0-gt1-gt0 or 1-gt0-gt1
  • The energy of a single transition

57
Trends in Power and Energy
  • The power required per transistor
  • For a fixed task, slowing clock rate (frequency)
    reduces power, but not energy.

58
Trends in Power and Energy
  • Example
  • some microprocessors with adjustable voltage
  • 15 reduction in voltage -gt 15 reduction in
    frequency
  • the impact on dynamic energy and dynamic power?

59
Trends in Power and Energy
  • Answer

60
Trends in Power and Energy
  • Challenges
  • distributing the power
  • removing the heat
  • preventing hot spots
  • potential research topics

61
Trends in Power and Energy
  • Energy-efficiency improvement techniques
  • 1. do nothing well
  • turn off the clock of inactive modules
  • 2. DVFS dynamic voltage-frequency scaling
  • scale down clock frequency and voltage during
    periods of low activity

62
DVFS
63
Trends in Power and Energy
  • Energy-efficiency improvement techniques
  • 3. design for typical case
  • PMDs, laptops often idle
  • memory and storage with low power modes to save
    energy
  • 4. overclocking
  • the chip runs at a higher clock rate for a short
    time until temperature rises

64
Trends in Cost
  • Cost of an Integrated Circuit
  • wafer for test chopped into dies for
  • packaging

65
Trends in Cost
  • Cost of an Integrated Circuit

percentage of manufactured devices that
survives the testing procedure
66
Trends in Cost
  • Cost of an Integrated Circuit

67
Trends in Cost
  • Cost of an Integrated Circuit

68
Intel Core i7 Die
69
Trends in Cost
  • Example

70
(No Transcript)
71
Trends in Cost
  • Example

72
Trends in Cost
  • Cost of an Integrated Circuit
  • N process-complexity factor for measuring
    manufacturing difficulty

73
Outline
  • Classes of computers
  • Parallelism
  • Instruction Set Architecture
  • Trends
  • Dependability
  • Performance Measurement

74
Dependability
  • SLA service level agreements
  • System states up or down
  • Service states
  • service accomplishment
  • service interruption

failure
restoration
75
Dependability
  • Two measures of dependability
  • Module reliability
  • Module availability

76
Dependability
  • Two measures of dependability
  • Module reliability
  • continuous service accomplishment from a
    reference initial instant
  • MTTF mean time to failure
  • MTTR mean time to repair
  • MTBF mean time between failures
  • MTBF MTTF MTTR

77
Dependability
  • Two measures of dependability
  • Module reliability
  • FIT failures in time
  • failures per billion hours
  • MTTF of 1,000,000 hours
  • 109/106
  • 1000 FIT

78
Dependability
  • Two measures of dependability
  • Module availability

79
Dependability
  • Example

80
Dependability
  • Answer

81
Outline
  • Classes of computers
  • Parallelism
  • Instruction Set Architecture
  • Trends
  • Dependability
  • Performance Measurement

82
Measuring Performance
  • Execution time
  • the time between the start and the completion of
    an event
  • Throughput
  • the total amount of work done in a given time

83
Measuring Performance
  • Computer X and Computer Y
  • X is n times faster than Y

84
Quantitative Principles
  • Parallelism
  • Locality
  • temporal locality recently accessed items are
    likely to be accessed in the near future
  • spatial locality items whose addresses are near
    one another tend to be referenced close together
    in time

85
Quantitative Principles
  • Amdahls Law

86
Quantitative Principles
  • Amdahls Law two factors
  • 1. Fractionenhanced
  • e.g., 20/60 if 20 seconds out of a 60-second
    program to enhance
  • 2. Speedupenhanced
  • e.g., 5/2 if enhanced to 2 seconds while
    originally 5 seconds

87
(No Transcript)
88
Quantitative Principles
  • Example

89
Quantitative Principles
  • The Processor Performance Equation

90
(No Transcript)
91
Quantitative Principles
  • Example

92
Quantitative Principles
  • Example

93
?
94
Reading
  • Chapter 1.8, 1.10 1.13
About PowerShow.com