A History of Microprocessors

Every once in a while, someone will send me a truly interesting link. Having seen a few innovations myself and possessing a strong interest in history, I read the CPU DB: Recording Microprocessor History on the Association for Computing Machinery (ACM) site with great interest. The post is a bit long, but essentially, the work by Andrew Danowitz, Kyle Kelley, James Mao, John P. Stevenson, and Mark Horowitz does something that no other site does, it provides you with a comprehensive view of 790 different microprocessors created since the introduction of Intel’s 4004 in November 1971. The CPU DB is available for anyone to use and should prove useful for scientist, developer, and hobbyist alike.

Unlike a lot of the work done on microprocessors, this one hasn’t been commissioned by a particular company. In fact, you’ll find processors from 17 different vendors. The work also spans a considerable number of disciplines. For example, you can discover how the physical scaling of devices has changed over the years and the effects of software on processor design and development.

A lot of the information available in this report is also available from the vendor or a third party in some form. The problem with vendor specification sheets and third party reports is that they vary in composition, depth, and content—making any sort of comparison extremely difficult and time consuming. This database makes it possible to compare the 790 processors directly and using the same criteria. A researcher can now easily see the differences between two microprocessors, making it considerably easier to draw conclusions about microprocessor design and implementation.

Not surprisingly, it has taken a while to collect this sort of information at the depth provided. According to the site, this database has been a work in progress for 30 years now. That’s a long time to research anything, especially something as esoteric as the voltage and frequency ranges of microprocessors. The authors stated their efforts were hampered in some cases by the age of the devices and the unavailability of samples for testing. I would imagine that trying to find a usable copy of a 4004 for testing would be nearly impossible.

You’ll have to read the report to get the full scoop of everything that CPU DB provides. The information is so detailed that the authors resorted to using tables and diagrams to explain it. Let’s just say that if you can’t find the statistic you need in CPU DB, it probably doesn’t exist. In order to provide a level playing field for all of the statistics, the researchers have used standardized testing. For example, they rely on the Standard Performance Evaluation Corporation (SPEC) benchmarks to compare the processors. Tables 1 and 2 in the report provide an overview of the sorts information you’ll find in CPU DB.

This isn’t a resource I’ll use every day. However, it is a resource I plan to use when trying to make sense of performance particulars. Using the information from CPU DB should remove some of the ambiguity in trying to compare system designs and determine how they affect the software running on them. Let me know what you think of CPU DB at John@JohnMuellerBooks.com.