Beyond Moore's law: Internet growth trends

To keep pace with the Internet's growth, the maximum speed of core routers and switches must increase at the same rate. In a study conducted in 1969, the author analyzed 39 scientific computers released or planned for release from 1958 to 1972 to determine optimal computer replacement strategy (http://www.ziplink.net/lroberts/Forecast69.htm). This study looked at the trend of CPU throughput per dollar and predicted that computer performance would double every 18.6 months. Updating the study using data for 1999 PCs shows that the trend over 41 years is a doubling of computer performance every 21 months, a remarkably small correction. A similar study tracking the costs from the first ARPA packet switches in 1969 to the most modern routers and ATM switches in 1999 confirms that packet switches have followed the same trend as computers, with performance per dollar doubling every 21 months. Although the computer performance rate predicted in the updated 1969 study is similar to Moore's law, the trends are not identical. It would appear that both the performance per dollar for computers and the serial interface speed for communications are increasing at 94 percent of the yearly growth rate of semiconductor performance. We can use this information about performance and cost trends to predict the cost of computers and communications and to understand the Internet traffic growth. Keeping up with these trends will be a major engineering challenge.