1 Fundamentals of Computer Design
And now for something completely different.
Monty Python’s Flying Circus
1.1
Introduction
1
1.2
The Task of a Computer Designer
4
1.3
Technology Trends
11
1.4
Cost, Price and their Trends
14
1.5
Measuring and Reporting Performance
25
1.6
Quantitative Principles of Computer Design
40
1.7
Putting It All Together: Performance and Price-Performance
49
1.8
Another View: Power Consumption and Efficiency as the Metric
58
1.9
Fallacies and Pitfalls
59
1.10
Concluding Remarks
69
1.11
Historical Perspective and References
70
Exercises
77
Computer technology has made incredible progress in the roughly 55 years since
the first general-purpose electronic computer was created. Today, less than a
thousand dollars will purchase a personal computer that has more performance,
more main memory, and more disk storage than a computer bought in 1980 for
$1 million. This rapid rate of improvement has come both from advances in the
technology used to build computers and from innovation in computer design.
Although technological improvements have been fairly steady, progress aris-
ing from better computer architectures has been much less consistent. During the
first 25 years of electronic computers, both forces made a major contribution; but
beginning in about 1970, computer designers became largely dependent upon in-
tegrated circuit technology. During the 1970s, performance continued to improve
at about 25% to 30% per year for the mainframes and minicomputers that domi-
nated the industry.
The late 1970s saw the emergence of the microprocessor. The ability of the
microprocessor to ride the improvements in integrated circuit technology more
closely than the less integrated mainframes and minicomputers led to a higher
rate of improvement—roughly 35% growth per year in performance.
1.1 Introduction
2
Chapter 1 Fundamentals of Computer Design
This growth rate, combined with the cost advantages of a mass-produced
microprocessor, led to an increasing fraction of the computer business being
based on micro