It has a single PCIe X4 slot, but the slot is open-ended — this means you can still connect an X16 card to it. Pineboards connected an AMD Radeon RX 460 GPU (the specific card appears to be made ...
PCI Express ... (x1, x4, x8 or x16) will fit and work in an x16 slot (mechanical), smaller slots may not physically allow a larger card to fit. Some connectors have an ‘open-ended ...
As long as you accept needing to supply external power with even a low-end GT 1030 card ... used also offered PCIe, the same card was run in a PCIe x4 slot, as well as in an x1 configuration ...