Is 7010's PCIe x16 slot only Gen ? Can I upgrade to ?

PCIe slots allow your motherboard to connect with your PC's most critical components and provide key functionality

GPUs are usually installed in the top x16 slot, as it has the most bandwidth and, traditionally, the most direct connection to the CPU Modern PCIe SSDs use

pcie4 slot your i5-3470 works on PCIe natively, Optiplex 7010 has only one slot bound to CPU PCIe, others are linked via chipset

pci e slot However, there is usually a cost increase incurred with higher lane counts PCIe Slot Differences Photo from 20050531pci-express-cards