ing their systems accordingly: a high-end system may be, on the average, 10 percent faster and 30 percent more expensive than the next-best. That behavior has dovetailed perfectly with the underlying technology development in the computers—as ever-faster silicon technology has become available, faster and faster computers could be designed. It is the nature of the semiconductor manufacturing process that silicon chips coming off the fabrication line exhibit a range of speeds. Rather than discard the slower chips, the manufacturer simply charges less for them. Ever-rising performance has been the wellspring of the entire computer industry. Meanwhile, the improving economics of ever-larger shipment volumes have driven overall system costs down, reinforcing a virtuous spiral2 by making computer systems available to lower-price, larger-unit-volume markets.

For their part, computer buyers demand ever-faster computers in part because they believe that using faster machines confers on them an advantage in the marketplace in which they compete.3 Applications that run on a particular generation of computing system may be impractical or not run at all on a system that is only one-tenth as fast, and this encourages hardware replacements for performance every 3-5 years. That trend has also encouraged buyers to place a premium on fast new computer systems because buying fast systems will forestall system obsolescence as long as possible. Traditionally, software providers have shown a tendency to use exponentially more storage space and central processing unit (CPU) cycles to attain linearly more performance; a tradeoff commonly referred to as bloat. Reducing bloat is another way in which future system improvements may be possible. The need for periodic replacements exists whether the performance is taking place on the desktop or in the “cloud”


2A small number of chips are fast, and many more are slower. That is how a range of products is produced that in total provide profits and, ultimately, funding for the next generation of technology. The semiconductor industry is nearing a point where extreme ultraviolet (EUV) light sources—or other expensive, exotic alternatives—will be needed to continue the lithography-based steps in manufacturing. There are a few more techniques left to implement before EUV is required, but they are increasingly expensive to use in manufacturing, and they are driving costs substantially higher. The future scenario that this implies is not only that very few companies will be able to manufacture chips with the smallest feature sizes but also that only very high-volume products will be able to justify the cost of using the latest generation of technology.

3For scientific researchers, faster computers allow larger or more important questions to be pursued or more accurate answers to be obtained; office workers can model, communicate, store, retrieve, and search their data more productively; engineers can design buildings, bridges, materials, chemicals, and other devices more quickly and safely; and manufacturers can automate various parts of their assembly processes and delivery methods more cost-effectively. In fact, the increasing amounts of data that are generated, stored, indexed, and retrieved require continued performance improvements. See Box 1.1 for more on data as a performance driver.

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