PCI, or Peripheral Component Interconnect, is a parallel bus architecture developed in 1992 and is the predominant local bus designed in PCs and server platforms today. Over the years, the PCI-SIG has made numerous improvements to this technology and extended its application.
PCI Express is the official name for the architecture formerly known by the code name third generation I/O or 3GIO architecture. The name and its associated logo is a trademark of the PCI-SIG. The name reflects the high-speed, point-to-point qualities of the new architecture, and acknowledges that software compatibility is maintained between PCI and PCI Express.
The PCI Express 1.0 specifications are comprised of the core 'Base' and 'Card Electromechanical' specifications. The Base specification describes the protocol, signaling, software and other aspects of the technology while the Card Electromechanical specification describes the ATX-based form factors. The PCI Express specifications were developed by the Arapahoe Working Group (AWG) and transferred to the PCI-SIG with the approval of its Board of Directors. The specifications have been reviewed by the general membership of the PCI-SIG, ratified by the PCI-SIG Board of Directors and are now available worldwide for use in computing and communications platforms. These specifications will be maintained and enhanced by the PCI Express workgroup established in the PCI-SIG.The demands of emerging computing and communications platforms exceed the capabilities of the traditional PCI bus. Technical innovations such as 10 GHz+ CPU speeds, faster memory, high performance graphics, gigabit networking, high-speed consumer devices and other market requirements will drive the need for much greater internal system bandwidth. The PCI Express architecture is a lowcost, highly scalable, general-purpose serial I/O interconnect that provides a unifying standard for consolidating a number of I/O solutions within a platform. For example, PCI Express can be used to replace the existing PCI, AGP and core logic interconnects.