HP EliteDesk 800 G9 Mini — one M.2 for storage, one for Wi-Fi, no PCIe

The G9 Mini has one M.2 2280 slot for storage and a separate M.2 2230 slot for a Wi-Fi and Bluetooth combo card. That’s the full extent of its expandability — no additional slots are available in this compact chassis, so what you configure at purchase is largely what you get.