Embedded motherboard designs change slowly when it comes to peripheral interfaces. ISA-based interfaces like PC/104-Plus remain because it supports legacy boards and it is easy to design peripheral boards, but the interface for the future is PCI Express (PCIe). While there are a host of PCIe daughter board options, the Mini-PCIe form factor offers a compact expansion option for embedded motherboards.
A single Mini-PCIe socket has been commonly found on embedded motherboards for some time, but the number of sockets is increasing as developers are finding more ways to embed peripherals via Mini-PCIe modules. These can often replace the peripherals on legacy boards that take up significantly more space and use more power. The x1 PCIe interface provides sufficient bandwidth for high-speed peripherals, and the multifunction socket can often support interface like SATA in the form of mSATA modules.