What Is PCIe x16 ? -

The system also provides extensive functional expansion options, including one PCIe slot, an 2230 E-Key for Wi-Fi, and an 3042

You can plug anything you want into that slot pcie 123 are forward and backward compatible; no issue there While the slot is full X16 length

pcie 40 in 30 slot You can plug anything you want into that slot pcie 123 are forward and backward compatible; no issue there While the slot is full X16 length

pcie x4 in x16 slot Best AMD AM4 B550 MATX motherboard, lightning PCIe , lightning , USB Gen 1, heatsink, wifi AC, powerful overclocking, MSI PRO