| PCI Local Bus | |
 PCI-X motherboard, with one card installed. | |
| Year created | 1998 |
|---|---|
| Created by | IBM, HP, and Compaq |
| Superseded by | PCI Express (2004) |
| Width in bits | 64 |
| Speed | Half-duplex[1] 266–4266 MB/s |
| Style | Parallel |
| Hotplugging interface | Optional |
PCI-X, short for Peripheral Component Interconnect eXtended, is a computer bus and expansion card standard that enhances the 32-bit PCI local bus for higher bandwidth demanded mostly by servers and workstations. It uses a modified protocol to support higher clock speeds (up to 133 MHz), but is otherwise similar in electrical implementation. PCI-X 2.0 added speeds up to 533 MHz,[2]: 23 with a reduction in electrical signal levels.
The slot is physically a 3.3 V PCI slot, with exactly the same size, location and pin assignments. The electrical specifications are compatible, but stricter. However, while most conventional PCI slots are the 85 mm long 32-bit version, most PCI-X devices use the 130 mm long 64-bit slot, to the point that 64-bit PCI connectors and PCI-X support are seen as synonymous.
PCI-X is in fact fully specified for both 32- and 64-bit PCI connectors,[3]: 14 and PCI-X 2.0 added a 16-bit variant for embedded applications.[2]: 22
It has been replaced in modern designs by the similar-sounding PCI Express (officially abbreviated as PCIe),[4] with a completely different physical connector and a very different electrical design, having one or more narrow but fast serial connection lanes instead of a number of slower connections in parallel.
- ^ "PCIe (Peripheral Component Interconnect Express) | On the Motherboard | Pearson IT Certification". www.pearsonitcertification.com. Retrieved 2020-09-25.
- ^ a b Cite error: The named reference
PCIX2.0was invoked but never defined (see the help page). - ^ Cite error: The named reference
PCIX1.0awas invoked but never defined (see the help page). - ^ Jean Andrews (2010). A+ Guide to Managing and Maintaining Your PC. Cengage Learning. p. 187. ISBN 978-1-4354-9778-8.