PCI-X 2.0 Overview†

PCI-X 2.0 is a new, higher speed version of the conventional PCI standard, which supported signaling speeds up to 533 megatransfers per second (MTS).
Revision 1.0 of the PCI-X specification defined PCI-X 66 and PCI-X 133 devices that transferred data up to 133 MTS, or over 1Gbyte per second for a 64-bit device.
The present revision adds two new speed grades: PCI-X 266 and PCI-X 533, offering up to 4.3 gigabytes per second of bandwidth, 32 times faster than the first generation of PCI.
Another major feature of the PCI-X 2.0 specification is enhanced system reliability.
ECC support has been added both for the header and payload, providing automatic single-bit error recovery and double-bit error detection.
These new standards keep pace with upcoming advances in high-bandwidth business-critical applications such as Fibre Channel, RAID, networking, InfiniBand Architecture, SCSI, and iSCSI.
PCI-X 2.0 is built upon the same architecture, protocols, signals, and connector as traditional PCI. The reuse of many of the design elements from the conventional PCI and PCI-X1.0b standards eases design and implementation migration. Migration to PCI-X 266 and PCI-X 533 is further simplified by retaining hardware and software compatibility with previous generations of PCI and PCI-X. As a result, new designs can immediately connect with hundreds of PCI and PCI-X products that are currently available.
The combination of backwards compatibility and ease of migration provides investment protection for customers, developers, and manufacturers of existing PCI and PCI-X technologies as they migrate to PCI-X 266 and PCI-X 533.

PCI-X 2.0 also includes new features that will enhance applications in the future. It defines a new 16-bit interface width specifically designed for those applications that are constrained by space, such as embedded RAID controllers, or portable applications.
PCI-X 2.0 also expands the device configuration space for each device-function to 4Kbytes, and defines a new Device ID Message transaction to enable simplified peer-topeer transactions for applications such as streaming-media.

For over ten years, the PCI-SIG has been developing the world?s most popular bus technology. The PCI-X 2.0 266 MHz and 533 MHz standards lay the groundwork for the next decade, and further backwards-compatible extensions are planned beyond 533 MHz.

Summary of PCI-X 2.0 Features

  • Doubles and Quadruples PCI-X bandwidth.
  • Full hardware and software backward compatibility to previous generations of PCI.
  • Builds upon tens of man-centuries of development.
  • Uses the same form factor, pin-outs, connector, bus widths, and protocols.
  • Enables 10Gb Ethernet, 10Gb Fibre Channel, InfiniBand? Architecture, and other IO technologies.
  • Full RAS support including ECC.
  • Performance 32 times higher than the first generation of PCI.