PCIe 4 vs PCIe 3: Do you need Gen 4 in 2020?

Slot are either PCIe or depending on riser selection and rear drive bay selection The use of some slots requires two processors Slots are configured

Yes, you can use a PCIe graphics card in a PCIe slot PCIe slots are backward compatible with PCIe cards, meaning they can still work together

pcie slot sizes AU Viewer MSI B550 & AMD Ryzen Deal: PCCGEdge3700XDeal MSI B550

pcie 4 slot  It's not a question of efficiency ( whether or not it's justifiable to use expensive card designed for 16x PCIe in 4x slot of PCIe