Advanced Computer Architecture

• Fundamental of Computer Design• Instruction Set Principles and Examples• Pipelining:Basic and Intermediate Concepts• Memory Hierarchy Design• Storage System• Instruction-Level Parallelism:Concepts and

Challenges• Exploiting Instruction-Level Parallelism with

Software Approaches• Multiprocessors and Thread-Level Parallelism

Forces on Computer Architecture

ComputerArchitecture

Technology ProgrammingLanguages

OperatingSystems

History

Applications

(A = F / M)

Fundamentals of Computer Design

• Introduction• The Task of the Computer Designer• Technology Trends• Cost Price, and Their Trends• Performance• Quantitative Principles of Computer Design• Putting It All Together: Performance and Price-

Performance• Power Consumption and Efficiency• Fallacies and Pitfalls

Microprocessor Performance

Cost of Downtime

System Characteristics of the the Three Computing Classes

Technology Trends• Clock Rate: ~30% per year• Transistor Density: ~35%• Chip Area: ~15%• Transistors per chip: ~55%• Total Performance Capability: ~100%• by the time you graduate...

– 3x clock rate (3-4 GHz)– 10x transistor count (1 Billion transistors)– 30x raw capability

• plus 16x DRAM density, 32x disk density

The Most Important Functional Requirements and Architect Faces

1.4 Cost, Price, and Their TrendsPrices of six generation of DRAMS

The Price of an Intel Pentium III over Time

What is “Computer Architecture”?

• Coordination of many levels of abstraction• Under a rapidly changing set of forces• Design, Measurement, and Evaluation

I/O systemInstr. Set Proc.

Compiler

OperatingSystem

Application

Digital DesignCircuit Design

Instruction Set Architecture

Firmware

Datapath & Control

Layout

Computer Architecture Topics

• NetworksM

Interconnection NetworkS

PMPMPMP° ° °

Topologies,Routing,Bandwidth,Latency,Reliability

Processor-Memory-Switch

MultiprocessorsNetworks and Interconnections

Network Interfaces

Shared Memory,Message Passing,Data Parallelism

Photograph of an Intel Pentium 4

This 8-inch Wafer Contains 564 MIPS64 20k Processors

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Estimated distribution of PC Costs

DropCostRAM

The components of price for a $1000 PC

1.5 Measuring and Reporting Performance: Execution Time

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Y

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The programs in the SPEC CPU 2000 benchmark suites

The Embedded Benchmark

EEMBC:The EDN Embedded Microprocessor Benchmarks ConsortiumEEMBC:The EDN Embedded Microprocessor Benchmarks Consortium

The machine, software, and baseline tuning parameters for the CINT2000

Comparing and Summarizing Performance

Weighted arithmetic mean execution for three machines

Execution times from Figure 1.15 normalized to each machine

1.6 Quantitative Principles of Computer Design

• Amdahl’s Law

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Amdahl’s Law

• Enhancement more, Improvement more

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Amdahl’s Law (Page41)

Performance Comparison-Speedup Amdahl’s Law

The CPU Performance Equation(Page42)

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timecycleClockCPIICtimeCPU

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CPU time

• Clock cycle time---Hardware technology and organization

• CPI---Organization and instruction set architecture

• Instruction count---Instruction set architecture and compiler technology

Overall CPI

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CPI Com.

Speedup

• Pipeline(Operation manual,Regular design ,…)

• Principle of locality-Temporal and Spatial

• Parallelism-Multiple Units, processors and Cluster Servers, Distributed Computing,…

• Clock Rate ,(Circuits, Devices,…..)

• Optics,…..

1.7 Performance and Price-performance Seven different desktop systems

Performance and price-performance

Performance and price-performance

Cluster Systems

The performance and the price-performance of cluster systems

Price-performance of cluster systems

Five different embedded processors

Relative performance of five different embedded processors for three of the five EEMBC

benchmark suites

EEMBC:The EDN Embedded Microprocessor Benchmarks Consortium

Relative price-performance of five different embedded processors for three of the five

EEMBC benchmark suites

1.8 Power Consumption and Efficiency as the metric

1.9 Fallacies and Pitfalls

• Fallacies—misbelieves(F)• Pitfalls---Easily made mistakes(P)

– The relative performance of two processors with the same instruction set architecture(ISA) can be judged by clock rate or by the performance of a single benchmark suite. (F)(Fig.1.28)

– Benchmarks remain valid indefinitely. (F)(Fig. 1.29)– Comparing hand-coded assembly and compiler-generated

high-level language performance.(P)– Peak performance tracks observed performance. (F)

1.9 Fallacies and Pitfalls

• The Best design for a computer is the one that optimizes the primary objective without considering implementation.(F)

• Neglecting the cost of software in either evaluating a system or examining cost-performance. (P)

• Falling prey to Amdahl’s Law.(P)• Synthetic benchmarks predict performance for real

programs.

1.9 Fallacies and Pitfalls

• MIPS is an accurate measure for computing performance among computers.(F)

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1.9 Fallacies and Pitfalls

• The problem with using MIPS as a measure for comparison– MIPS is dependent on the instruction set,

making it difficult to compare MIPS of computer with different instruction sets.

– MIPS varies between programs on the same computer.

– Most importantly, MIPS can vary inversely to performance

P4 and P3 performance comparison-Relative performance

The tuning parameters for the SPEC CFP2000 report

The evolution of the SPEC benchmarks

over time

The performance of three embedded processors

Measurements of peak performance and actual performance

1.10 Concluding Remarks

• Make the common case fast• Chap. 2:The interaction between compiler

and instruction set design.• Part 3: Pipeline(Appendix A)• Part 4: Memory Design(Chap.5)• Part 5: Storage System (Chap. 7)• (Page1-86),(page87-168),(page A-1~A-87)

…..

1.11 Historical Perspective and References

• The First General-purpose Electronic Computers

• Important special-purpose machines

• Commercial Developments

• Development of Quantitative Performance Measures:Successes and Failures

reference

reference

MM MIPS

ePerformancePerformanc

MIPS