ASRock DeskMini 110 — no PCIe slots, one M.2 and one 2.5-inch bay

The DeskMini 110 has no PCIe expansion slots at all — just one M.2 NVMe slot and one 2.5-inch SATA bay for storage. The M.2 slot can also take a Wi-Fi card (like the Intel 3168) if you don’t need it for storage, giving you a little flexibility in a very compact chassis.