What Are PCIe Slots Used For? - Devices and Expansion

Explaining PCIe Slots pcie 2 0 x1 slot PCI Slot x 3 30423052 B-Key x 1 Mini PCIe Slot x 1 Micro SIM Card Slot x 1 pcie slot length 4x is overkill, you could handle 8 NICS on that but I've never seen a 2x slot so that's why they're using 4x Presumably they make 4-port

pcie 20 x16 slot microSD card slot, with support for high-speed SDR104 mode 2 × USB PCIe x1 interface for fast peripherals (requires separate HAT or