miniPCIe

Mini PCI Express (mPCIe) is a hardware expansion standard defined by PCI-SIG for a small form-factor card and corresponding edge connector used in laptops, tablets, and embedded systems. It evolved from the original Mini PCI design and provides a modular way to add PCI Express devices without large motherboard changes. The standard specifies two commonly used card sizes—half-size and full-size—and a 52-pin edge connector that carries PCI Express signals, usually a PCIe x1 link, along with USB 2.0 signals and other management lines.

A mini PCIe card typically uses a PCI Express interface (often x1) to communicate with the host, with the connector also carrying USB 2.0 and other signals as defined by the specification. Cards are secured to the motherboard by a retaining screw, and installations are normally performed with the system powered down, though some platforms may support hot-swapping depending on firmware and driver support.

Common uses for mPCIe cards include wireless network adapters (Wi‑Fi and Bluetooth), cellular modems, GPS, and, in some cases, small solid-state storage devices. The form factor is not compatible with standard PCIe slots or with the earlier Mini PCI, due to different physical connectors and electrical interfaces.

In modern devices, mini PCIe has largely been superseded by the M.2 (NGFF) standard, which offers higher bandwidth and more flexible keying. Nevertheless, mPCIe remains prevalent in older laptops, many embedded boards, and industrial computers, and adapters exist to bridge mPCIe devices to other interfaces when needed.