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MoboCop · 10-06-2004 · Category: Tech-planations


PCI was originally developed through the efforts of Intel and other industry leaders in response to the realization that ISA, a bus design developed in 1984, was becoming a bottleneck within the computer. Intel wanted a high-performing bus and thought the best solution would be to pursue an industry standard. Having a standard would prevent the complication of competing buses and consumer confusion. A technology under development in Intel research and development seemed the perfect solution, offering both superior performance and plug-and-play capabilities. Intel spurred the industry by:

  • Forming a PCI special interest group (PCI-SIG) with others in the industry.
  • Contributing the technology from Intel research and development.
  • Encouraging an open industry specification.
  • Implementing the new specification in Intel product groups, ensuring ease of implementation and availability.

The result was PCI one of the most (if not the most) successful chip and board interconnect technologies in history. PCI provided a tenfold performance gain over ISA, and its plug-and-play capabilities made it easier for users to add cards to their computers. Developed initially for personal computer applications, PCI is used today in almost every computing platform.

As fast as technology has evolved and advanced over the last 12 years, it's surprising how long PCI has lasted. PCI's longevity can be attributed to the PCI-SIG and two characteristics of PCI. The first is that PCI is processor-agnostic both to frequency and voltage so it could function in the desktop, mobile and server markets with little or no change. It wasn't wired into a specific processor, so manufacturers could standardize their I/O across multiple product groups and generations. That also meant computer manufacturers wouldn't have to redesign their PC architecture every time Intel came out with a new chip. The second characteristic is that PCI is flexible in its ability to support multiple form factors. PCI-SIG members were able to define connectors, add-in cards and I/O brackets to standardize the I/O back panel and form factors for the server, desktop and mobile markets. This standardization made the distribution of PCI-based add-in cards and form factor-based computer chassis possible through the consumer channel and in sufficient volumes to meet consumer price targets.


  1. Introduction
  2. VESA Local Bus
  3. PCI
  4. AGP
  5. PCI Express

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