PCI Express
computer expansion bus standard
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe, is a high-speed standard used to connect hardware components inside computers. It is designed to replace older expansion bus standards such as PCI, PCI-X and AGP. Developed and maintained by the PCI-SIG (PCI Special Interest Group), PCIe is commonly used to connect graphics cards, sound cards, Wi-Fi and Ethernet adapters, and storage devices such as solid-state drives and hard disk drives.
Compared to earlier standards, PCIe supports faster data transfer, uses fewer pins, takes up less space, and allows devices to be added or removed while the computer is running (hot swapping). It also includes better error detection and supports newer features like I/O virtualization for advanced computing needs.
PCIe connections are made through lanes, which are pairs of conductors that send and receive data. Devices can use one or more lanes depending on how much data they need to transfer. PCIe technology is also used in laptop expansion cards (like ExpressCard) and in storage connectors such as M.2, U.2, and SATA Express.
Architecture
Conceptually, the PCI Express bus is a high-speed serial replacement of the older PCI/PCI-X bus. One of the key differences between the PCI Express bus and the older PCI is the bus topology; PCI uses a shared parallel bus architecture, in which the PCI host and all devices share a common set of address, data, and control lines. In contrast, PCI Express is based on point-to-point topology, with separate serial links connecting every device to the root complex (host).
Begin with the source’s own compact description: “PCI Express” is computer expansion bus standard. The dossier treats that line as a proposition to test through Express, computer and expansion, not as a finished interpretation.
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The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Aug 28, 2026. The linked authority identifier is Q206924. None of the 2 selected statements returned an explicit reference.
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This entry incorporates text from “PCI Express” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.