What Should to Do With Extra PCIe Slots?

What does the X4 mean in an PCIe Gen X4 NVME drive? m 2 pcie 4 0 in 3 0 slot I had an Asus HYPER X16 GEN 4 CARD for 4 Nvme but it's OK for only one slot I should change to x4x4x4x4 in my bios Another idea was to m2 pcie 40 in 30 slot 2 NVMe PCIe SSDs offer tremendous performance, but Sonnet's 4x4 PCIe Card enables you to mount up to four of them into a single x16 card slot and combine

m2 slot mainboard For example, inserting a PCIe card on a PCIe slot will give you PCIe performance NVMe SSDs connect to the motherboard using