What exactly does the spec “PCIe x16 slot ” mean?

The number of lanes that a PCIe device supports is typically expressed like “x4” for 4 lanes, “x8” for 8 lanes, and so on x1, x2, x4, x8, x16 PCIe Gen 3

So, to answer your original question, if you're happy to abandon any other PCI devices you currently have, you can choose a motherboard with more PCIe x1 slots;

169 jackpot slot Dave Prowse □ PCIe : Currently the king of expansion buses , PCI Express 1 has a data rate of 250 MB s per lane , version 2 is 500 MB s , and

128 slot Both the blue slots are PCIe x16 The difference is that the 2nd PCIe 16x is capable of wiring