PCI-X

Not to be confused with PCIe or PCI Express, PCI-X is a high performance bus that is designed to meet the increased I/O demands of technologies such as Fibre Channel, Gigabit Ethernet and Ultra3 SCSI often used in servers that was first developed by IBM, HP, and Compaq in 1998. PCI-X capabilities include the below features.

  • Up to 133 MHz bus speed
  • 64-Bit bandwidth
  • 1GB/sec throughput
  • More efficient bus operation for easier interface.
  • Split Transactions allows an indicator device to make only one data request and relinquish the bus, instead of constantly needing to poll the bus for a response.
  • Byte Count that enables indicator to specify, in advance, the specific number of bytes requested, eliminating the inefficiency of speculative prefetches.
  • Backwards compatibility

With the introduction of PCI Express, PCI-X is not as commonly found or used today.

Also see: Bus, Motherboard definitions, PCI