PCI Express
Peripheral Component Interconnect Express (PCI 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, hard disk drive host adapters, SSDs, Wi-Fi and Ethernet hardware connections.
PCI Express Media
Two types of PCIe slot on an Asus H81M-K motherboard
Various slots on a computer motherboard, from top to bottom: Template:Unordered list*
Example of the PCI Express topology:white "junction boxes" represent PCI Express device downstream ports, while the gray ones represent upstream ports.:7
PCI Express x1 card containing a PCI Express switch (covered by a small heat sink), which creates multiple endpoints out of one endpoint and lets multiple devices share it
The PCIe slots on a motherboard are often labeled with the number of PCIe lanes they have. Sometimes what may seem like a large slot may only have a few lanes. For instance, a x16 slot with only 4 PCIe lanes (bottom slot) is quite common.
A PCI Express link between two devices consists of one or more lanes, which are dual simplex channels using two differential signaling pairs.:3
Highly simplified topologies of the Legacy PCI Shared (Parallel) Interface and the PCIe Serial Point-to-Point Interface
Intel P3608 NVMe flash SSD, PCI-E add-in card
8-pin (left) and 6-pin (right) power connectors used on PCI Express cards
