Computer Hardware

PCIe

Definition

PCI Express (Peripheral Component Interconnect Express) is a high-speed serial computer expansion bus standard. It is the primary interface for connecting high-speed components like graphics cards, NVMe SSDs, and network cards to the motherboard.

Why It Matters

PCIe is the data superhighway of a modern PC. Its high bandwidth and direct connection to the CPU are essential for the performance of the most demanding components.

Contextual Example

A graphics card is installed in a PCIe x16 slot, which gives it 16 "lanes" of data transfer for maximum throughput. An NVMe SSD might use a PCIe x4 slot.

Common Misunderstandings

  • Each new PCIe generation (e.g., 3.0, 4.0, 5.0) doubles the bandwidth per lane compared to the previous one.
  • The number of lanes (x1, x4, x8, x16) determines the total bandwidth for that slot.

Related Terms

Last Updated: December 18, 2025