Lectures of Hennessy

1. cse141: Introduction to
Computer Architecture
Steven Swanson
Hung-Wei Tseng
1

2. 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?
2

3. What is architecture?
• How do you build a machine that computes?
• Quickly, safely, cheaply, efficiently, in technology X, for
applicationY, etc.
Civilization advances by extending
the number of important
operations which we can perform
without thinking about them.
-- Alfred NorthWhitehead

4. Orientation
The internet

5. Orientation
The internet

6. Orientation
System Bus
(PCI)
IO
Power
Memory
Power
Memory
Memory Memory
Architecture begins about here.

7. Orientation
System Bus
(PCI)
IO
Power
Memory
Power
Memory
Memory Memory
Architecture begins about here.

10. You are here

11. You are here
cse141

12. The processors go here…

13. The processors go here…

14. Abstractions of the Physical World…
Physics/Materials Devices Micro-architecture ArchitecturesProcessors

15. Abstractions of the Physical World…
Physics/Materials Devices Micro-architecture ArchitecturesProcessors
This Course
cse241a/
ECE dept
Physics/
Chemistry/
Material science

16. …for the Rest of the System
Architectures
JVM
Processor
Abstraction
Compilers Languages
Software
Engineers/
Applications

17. …for the Rest of the System
Architectures
JVM
Processor
Abstraction
Compilers Languages
Software
Engineers/
Applications
cse130cse121 cse131 cseEverythingElse

18. Why study architecture?
11
• 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.

19. Performance andYou!
• Live Demo
12

20. 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

21. Building Chips

22. Building Chips
• Photolithography
Silicon Wafer

23. Building Chips
• Photolithography
Silicon Wafer Silicon Wafer
SiO2
Grow silicon dioxide

24. Building Chips
• Photolithography
Silicon Wafer Silicon Wafer
SiO2
Grow silicon dioxide
Silicon Wafer
SiO2
Resist
Apply photo resist

25. Building Chips
• Photolithography
Silicon Wafer Silicon Wafer
SiO2
Grow silicon dioxide
Silicon Wafer
SiO2
Resist
Apply photo resist
Silicon Wafer
SiO2
Resist
Mask Mask
Expose to UV

26. Building Chips
• Photolithography
Silicon Wafer Silicon Wafer
SiO2
Grow silicon dioxide
Silicon Wafer
SiO2
Resist
Apply photo resist
Silicon Wafer
SiO2
Resist
Mask Mask
Expose to UV
Silicon Wafer
SiO2
Patterned resist

27. Building Chips
• Photolithography
Silicon Wafer Silicon Wafer
SiO2
Grow silicon dioxide
Silicon Wafer
SiO2
Resist
Apply photo resist
Silicon Wafer
SiO2
Resist
Mask Mask
Expose to UV
Silicon Wafer
SiO2
Patterned resist
Silicon Wafer
Etch SiO2

28. Building Chips
• Photolithography
Silicon Wafer Silicon Wafer
SiO2
Grow silicon dioxide
Silicon Wafer
SiO2
Resist
Apply photo resist
Silicon Wafer
SiO2
Resist
Mask Mask
Expose to UV
Silicon Wafer
SiO2
Patterned resist
Silicon Wafer
Etch SiO2
Silicon Wafer
Met
Deposit metal

29. Building Chips
• Photolithography
Silicon Wafer Silicon Wafer
SiO2
Grow silicon dioxide
Silicon Wafer
SiO2
Resist
Apply photo resist
Silicon Wafer
SiO2
Resist
Mask Mask
Expose to UV
Silicon Wafer
SiO2
Patterned resist
Silicon Wafer
Etch SiO2
Silicon Wafer
Met
Deposit metal
Silicon Wafer
Met
Etch SiO2
(Or not)

30. Building Blocks:Transistors

31. Building Blocks:Wires

32. State of the art CPU
• 1-2 Billion xtrs
• 45nm features
• 3-4Ghz
• Several 100 designers
• >5 years
• $3Billion fab
• 70 GFLOPS
18

33. Current state of
architecture

34. Since 1940

35. Since 1940
• Plug boards -> Java
• Hand assembling -> GCC
• No OS -> WindowsVista

36. Since 1940
• Plug boards -> Java
• Hand assembling -> GCC
• No OS -> WindowsVista
Flexible performance is a liquid asset
• 50,000 x speedup
• >1,000,000,000 x density
(Moore’s Law)

37. Moore’s Law: Raw transistors

38. 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)

39. Computer Performance
23

40. Computer Performance
23
1
10
100
1000
10000
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT95
specINT2000
specINT2006

41. Computer Performance
23
1
10
100
1000
10000
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT95
specINT2000
specINT2006
1
10
100
1000
10000
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT95
specINT2000
specINT2006
47% per year

42. Computer Performance
23
1
10
100
1000
10000
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT95
specINT2000
specINT2006
1
10
100
1000
10000
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT95
specINT2000
specINT2006
47% per year
1
10
100
1000
10000
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT95
specINT2000
specINT2006
47% per year
39% per year

43. Computer Performance
23
1
10
100
1000
10000
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT95
specINT2000
specINT2006
1
10
100
1000
10000
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT95
specINT2000
specINT2006
47% per year
1
10
100
1000
10000
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT95
specINT2000
specINT2006
47% per year
39% per year
1
10
100
1000
10000
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT95
specINT2000
specINT2006
47% per year
39% per year
25% per year

44. The clock speed addiction
24
• 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.
0
1000
2000
3000
4000
5000
1996 1998 2000 2002 2004 2006 2008 2010
Clockspeed(Mhz)
Year
specINT2000
specINT2006

45. Power
25
Watts/cm2
1
10
100
1000
1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

46. Power
25
Watts/cm2
1
10
100
1000
1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

47. Power
25
Watts/cm2
1
10
100
1000
1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

48. Power
25
Watts/cm2
1
10
100
1000
1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

49. Power
25
Watts/cm2
1
10
100
1000
1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

50. Power
25
Watts/cm2
1
10
100
1000
1.5µ 1µ 0.7µ 0.5µ 0.35µ 0.25µ 0.18µ 0.13µ 0.1µ 0.07µ

51. 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?
26

52. 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
27

53. 28
Intel P4
1 core
Intel Core 2 Duo
2 cores
AMD Barcelona
4 cores
SPARC T1
8 cores
Intel Prototype
80 cores
Cell BE
8 + 1 cores
Intel Nahalem
4 cores

54. Computer Performance
29

55. Computer Performance
29
100
1000
10000
1996 1998 2000 2002 2004 2006 2008 2010
RelativePerformance
Year
specINT2000
specINT2006
39% per year
25% per year

56. 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.
30

57. What’s in this Class
31
• 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.

58. 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

59. 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
33

60. 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.
34

61. 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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