Nvidia A2000 in SFF - Precision 3450 PCIe x4 slot

What are PCIe Slots in PC? pcie 4 0 gpu in 3 0 slot Apparently the cross-compatibility and quality are quite variable PCIe = gen3 seems easier than gen4, though, and for your needs it sounds pcie 40 in 30 slot AMD RADEON RX AMD Radeon RX 550 4GB 128-Bit GDDR5 PCIe Low Profile Video Card GPU

pcie slot x16 PCI-E versions are Backwards Compatable it will work all you may get is limited Bandwidth from your PCI-E Slot to your PCI-E Graphics