cse141: Introduction to Computer Architecture

Steven SwansonHung-Wei Tseng

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Today’s Agenda

• What is architecture?• Why is it important?• At the highest level, where is architecture today?

Where is it going?• What’s in this class?

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What is architecture?

• How do you build a machine that computes?

• Quickly, safely, cheaply, efficiently, in technology X, for application Y, etc.

Civilization advances by extending the number of important

operations which we can perform without thinking about them.

-- Alfred North Whitehead

Orientation

The internet

Orientation

The internet

OrientationSystem Bus

(PCI)IO

Power

Memory

Power

Memory

Memory MemoryArchitecture begins about here.

OrientationSystem Bus

(PCI)IO

Power

Memory

Power

Memory

Memory MemoryArchitecture begins about here.

You are here

You are here

cse141

The processors go here…

The processors go here…

Abstractions of the Physical World…

Physics/Materials Devices Micro-architecture ArchitecturesProcessors

Abstractions of the Physical World…

Physics/Materials Devices Micro-architecture ArchitecturesProcessors

This Coursecse241a/ECE dept

Physics/Chemistry/

Material science

…for the Rest of the System

Architectures

JVM

Processor

AbstractionCompilers Languages

Software

Engineers/Applications

…for the Rest of the System

Architectures

JVM

Processor

AbstractionCompilers Languages

Software

Engineers/Applications

cse130cse121 cse131 cseEverythingElse

Why study architecture?

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• As CEs or CSs you should understand how computers work• Processors are the basis for everything in CS (except theory)• They are where the rubber meets the road.

• Performance is important• Faster machines make applications cheaper• Understanding hardware is essential to understanding how

systems behave

• It’s cool!• Microprocessors are among the most sophisticated devices

manufactured by people• How they work (and even that they work) as reliably and as

quickly as they do is amazing.

• Architecture is undergoing a revolution• The future is uncertain• Opportunities for innovation abound.

Performance and You!

• Live Demo

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Processor are Cool!

• Chips are made of silicon• Aka “sand”• The most adundant element in the

earth’s crust.• Extremely pure (<1 part per billion)• This is the purest stuff people make

Building Chips

Building Chips

• Photolithography

Silicon Wafer

Building Chips

• Photolithography

Silicon Wafer Silicon WaferSiO2

Grow silicon dioxide

Building Chips

• Photolithography

Silicon Wafer Silicon WaferSiO2

Grow silicon dioxideSilicon Wafer

SiO2Resist

Apply photo resist

Building Chips

• Photolithography

Silicon Wafer Silicon WaferSiO2

Grow silicon dioxideSilicon Wafer

SiO2Resist

Apply photo resistSilicon Wafer

SiO2Resist

Mask Mask

Expose to UV

Building Chips

• Photolithography

Silicon Wafer Silicon WaferSiO2

Grow silicon dioxideSilicon Wafer

SiO2Resist

Apply photo resistSilicon Wafer

SiO2Resist

Mask Mask

Expose to UV

Silicon WaferSiO2

Patterned resist

Building Chips

• Photolithography

Silicon Wafer Silicon WaferSiO2

Grow silicon dioxideSilicon Wafer

SiO2Resist

Apply photo resistSilicon Wafer

SiO2Resist

Mask Mask

Expose to UV

Silicon WaferSiO2

Patterned resistSilicon Wafer

Etch SiO2

Building Chips

• Photolithography

Silicon Wafer Silicon WaferSiO2

Grow silicon dioxideSilicon Wafer

SiO2Resist

Apply photo resistSilicon Wafer

SiO2Resist

Mask Mask

Expose to UV

Silicon WaferSiO2

Patterned resistSilicon Wafer

Etch SiO2Silicon Wafer

Met

Deposit metal

Building Chips

• Photolithography

Silicon Wafer Silicon WaferSiO2

Grow silicon dioxideSilicon Wafer

SiO2Resist

Apply photo resistSilicon Wafer

SiO2Resist

Mask Mask

Expose to UV

Silicon WaferSiO2

Patterned resistSilicon Wafer

Etch SiO2Silicon Wafer

Met

Deposit metalSilicon Wafer

Met

Etch SiO2(Or not)

Building Blocks: Transistors

Building Blocks: Wires

State of the art CPU

• 1-2 Billion xtrs• 45nm features• 3-4Ghz• Several 100 designers• >5 years• $3Billion fab• 70 GFLOPS

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Current state of architecture

Since 1940

Since 1940

• Plug boards -> Java

• Hand assembling -> GCC

• No OS -> Windows Vista

Since 1940

• Plug boards -> Java

• Hand assembling -> GCC

• No OS -> Windows Vista

Flexible performance is a liquid asset

• 50,000 x speedup

• >1,000,000,000 x density (Moore’s Law)

Moore’s Law: Raw transistors

The Importance of Architecture

• We design smarter and smarter processors

• Process technology gives us about 20% performance improvement per year

• Until 2004, performance grew at about 40% per year.

• The gap is due to architecture! (and compilers)

Computer Performance

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Computer Performance

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Computer Performance

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1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010

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The clock speed addiction

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• Clock speed is the biggest contributor to power• Chip manufactures (Intel, esp.) pushed clock speeds very

hard in the 90s and early 2000s.• Doubling the clock speed increases power by 2-8x• Clock speed scaling is essentially finished.

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Power

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Watts/cm 2

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1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

Power

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Watts/cm 2

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1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

Power

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Watts/cm 2

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1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

Power

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Watts/cm 2

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1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

Power

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Watts/cm 2

1

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1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

Power

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Watts/cm 2

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1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

What’s Next: Brainiacs

• Hold the clock rate steady.• Be smarter in silicon

• More sophisticated processors• More clever algorithms• This continues to deliver about 25% per year.• But for how long?

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What’s Next: Parallelism• This is all the rage right now• You probably own a multi-processor, they used to

be pretty exotic.• They provide some performance, but it’s hard to

use.• There aren’t that many threads• Remember, flexible performance is a liquid asset• Remember or look forward to cse121

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Intel P41 core

Intel Core 2 Duo2 cores

AMD Barcelona4 cores

SPARC T18 cores

Intel Prototype80 cores

Cell BE8 + 1 cores

Intel Nahalem4 cores

Computer Performance

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Computer Performance

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Course Staff

• Instructor: Steven Swanson• Lectures Tues + Thurs

• TA: Hung-Wei Tseng• Discussion sec: Wed. • (but not this week)

• See the course web page for contact information and office hours.

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What’s in this Class

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• Course outline• Instruction sets• The basics of silicon technology• Measuring performance• How processors work

• Basic pipelining• Data and control hazards• Branch prediction and speculation

• The memory system• Introduction to multiprocessors

• Weekly technology digressions• How various technologies actually work.

Your Tasks• Read the text!

• Computer Organization and Design: The Hardware/Software Interface (4th Edition) -- previous editions are not supported

• I’m not going to cover everything in class, but you are responsible for all the assigned text.

• Come to class!• I will cover things not in the book. You are responsible for

that too.• Class participation (5%)

• Homeworks throughout the course. (10%)• Weekly quizzes on Thursdays (10%)• One midterm. (25%)• One cumulative final. (35%)• One project (15%)

• Design your own ISA!32

The Link to 141L

• You do not need to take 141L along with 141, but you may need both to get your degree.

• The classes are mostly independent, except• The results of the project will be used in 141L• You can earn extra credit by licensing your ISA groups in

141L who are not in 141

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Grading

• Grading is on a 13 point scale -- F through A+• You will get a letter grade on each assignment• Your final grade is the weighted average of the

assignment grades.

• An excel spreadsheet calculates your grades• We will post a sanitized version online once a week.• It will tell you exactly where you stand.• It specifies the curves used for each assignment etc.

• OpenOffice doesn’t run it properly.

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Academic Honesty

• Don’t cheat.• Cheating on a test will get you an F in the class and no

option to drop, and a visit with your college dean.• Cheating on homeworks means you don’t have to turn

them in any more, but you don’t get points either. You will also take at least 25% penalty on the exam grades.

• Copying solutions of the internet or a solutions manual is cheating.

• Review the UCSD student handbook• When in doubt, ask. Honest mistakes will be

forgiven.

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