PCI Express
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e, is a high-speed serial computer expansion bus standard, designed to replace the older PCI, PCI-X and AGP bus standards. It is the common motherboard interface for personal computers' graphics cards, sound cards, hard disk drive host adapters, SSDs, Wi-Fi and Ethernet hardware connections. PCIe has numerous improvements over the older standards, including higher maximum system bus throughput, lower I/O pin count and smaller physical footprint, better performance scaling for bus devices, a more detailed error detection and reporting mechanism (Advanced Error Reporting, AER), and native hot-swap functionality. More recent revisions of the PCIe standard provide hardware support for I/O virtualization.
| Peripheral Component Interconnect Express | |
Logo | |
| Year created | 2003 |
|---|---|
| Created by | |
| Supersedes | |
| Width in bits | 1 per lane (up to 16 lanes) |
| No. of devices | 1 on each endpoint of each connection. |
| Speed | Dual simplex; examples in single-lane (x1) and 16-lane (x16), per direction:
|
| Style | Serial |
| Hotplugging interface | Yes (with ExpressCard, OCuLink, CFexpress or U.2) |
| External interface | Yes (with OCuLink or PCI Express External Cabling) |
| Website | pcisig |
The PCI Express electrical interface is measured by the number of simultaneous lanes. (A lane is a single send/receive line of data. The analogy is a highway with traffic in both directions.) The interface is also used in a variety of other standards — most notably the laptop expansion card interface called ExpressCard. It is also used in the storage interfaces of SATA Express, U.2 (SFF-8639) and M.2.
Format specifications are maintained and developed by the PCI-SIG (PCI Special Interest Group) — a group of more than 900 companies that also maintains the conventional PCI specifications.