Can I put a PCI-E x16 gpu in a PCI-E x16 slot?

Yes, a x1 card should work in a x16 slot It's good that you've got it to work in a x1 slot What else have you tried it in besides the x16 slot

4 Answers 4 · PCI-E x1 card will go in a x1, x4 or x16 slot · PCI-E x4 card will go in a x4 or x16 slot · PCI-E x16 card will only go in a x16

pcie slot gpu Graphics Cards · 5770 supports PCI Express up to x16 · Radeon RX 550 supports PCI Express up to x16 · PCI Express x16 is PCI Express

pcie x1 slot PCI Express x16 slot is required Table 31 provides the pin definitions of the required four special PCIe pins PCIe pin# Server Connection