Welcome to this book! We’re delighted to have this opportunity to convey the excitement of the world of computer systems. This is not a dry and dreary field, where progress is glacial and where new ideas atrophy from neglect. No! Computers are the product of the incredibly vibrant information technology industry, all aspects of which are responsible for almost 10% of the | Computer Abstractions Civilization advances and Technology by extending the number of important operations which we can perform without thinking about them. Alfred North Whitehead An Introduction to Mathematics 1911 Introduction 3 Below Your Program 10 Under the Covers 13 Performance 26 The Power Wall 39 The Sea Change The Switch from Uniprocessors to Multiprocessors 41 Real Stuff Manufacturing and Benchmarking the AMD Opteron X4 44 Fallacies and Pitfalls 51 Concluding Remarks 54 Historical Perspective and Further Reading 55 Exercises 56 Introduction Welcome to this book We re delighted to have this opportunity to convey the excitement of the world of computer systems. This is not a dry and dreary field where progress is glacial and where new ideas atrophy from neglect. No Computers are the product of the incredibly vibrant information technology industry all aspects of which are responsible for almost 10 of the gross national product of the United States and whose economy has become dependent in part on the rapid improvements in information technology promised by Moore s law. This unusual industry embraces innovation at a breathtaking rate. In the last 25 years there have been a number of new computers whose introduction appeared to revolutionize the computing industry these revolutions were cut short only because someone else built an even better computer. This race to innovate has led to unprecedented progress since the inception of electronic computing in the late 1940s. Had the transportation industry kept pace with the computer industry for example today we could travel from New York to London in about a second for roughly a few cents. Take just a moment to contemplate how such an improvement would change society living in Tahiti while working in San Francisco going to Moscow for an evening at the Bolshoi Ballet and you can appreciate the implications of such a change. 4 Chapter 1 Computer Abstractions and .
