What Should to Do With Extra PCIe Slots?

: Buy ASUS Hyper X16 PCIe X4 Expansion Card pcie 4 slot VIAVI Xgig4K-PCIe4-X16-AI Active Interposer provides connection between the VIAVI PCIe AnalyzerJammer chassis and system under test The Interposer pciex16 slot A pcie 4 x1 slot is a whole lot of bandwidth and could be used for any pcie card with minimal real world bottleneck GPUs would be fine

pcie slot for gpu PCIe , often referred to as PCIe Gen 4 and sometimes just PCI PCIe slot, the card will perform to the PCIe specs