Transcript Fundamentals of Design

Computer Architecture
Part I-A: Fundamentals of
Design
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The Food Chain
Big Fishes Eating Little Fishes
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Computer Food Chain
Massively Parallel Processors
Minisupercomputer
Mainframe
Server
Supercomputer
Minicomputer
Work- PC
station
Now who is eating whom?
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Why such a change?
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Performance
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Cost
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Technology advances
Computer architectural advances improves lowend
Simpler development
Higher volumes
Function
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Rise of interconnection technology
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Technology Trends:
Microprocessor Capacity
100000000
“Graduation Window”
Alpha 21264: 15 million
Pentium Pro: 5.5 million
PowerPC 620: 6.9 million
Alpha 21164: 9.3 million
Sparc Ultra: 5.2 million
10000000
Moore’s Law
Pentiu m
i80486
Transistors
1000000
i80386
i80286
100000
CMOS improvements:
• Die size: 2X every 3
yrs
• Line width: halve / 7 yrs
i8086
10000
i8080
i4004
1000
1970
1975
1980
1985
1990
1995
Year
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•logic capacity: 30%/year
•clock rate: at least 20%
per year
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Technology Trends Summary
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Memory
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DRAM capacity: about 60% per year
memory speed: about 10% per year
cost per bit: improves about 25% per
year
Disk
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capacity: about 60% per year
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Log of Performance
Performance Trends
Supercomputers
Mainframes
Minicomputers
Microprocessors
Year
1970
1975
1980
1985
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1990
1995
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Processor Performance (SPEC)
350
processor performance:
1.35x before, 1.58x now (about 2x every 1.5 years)
300
RIS C
Performance
250
RISC
introduction
200
150
Inte l x86
100
35%/yr
50
0
1982
1984
1986
1988
1990
1992
1994
Ye ar
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The Designer’s Task
Technology
Programming
Languages
Applications
Computer
Architecture
Operating
Systems

History
Determine the attributes needed for a new machine,
then design a machine to maximize performance
while staying within cost constraints
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Functionality
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Designers must design a computer to meet
functional requirements as well as price and
performance goals.
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Application - How will the machine be used?
Operating System - Which OS to support?
Software - Will there be software for this
machine? Will it be compatible with existing
software?
Standards - Should the new machine adapt or
challenge existing standards?
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Software vs. Hardware
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Each feature can be implemented
either through hardware or software.
A hardware implementation is not
necessarily faster than a software one.
There must be balance between these
two implementations to meet
performance and cost goals.
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Designing Through Trends
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The designer must take notice of:
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hardware trends, especially the rapidly
occurring changes in implementation
technology
software trends and how programs will
use the machine
The designer must understand the
impact of these trends on machine
design.
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