What does the X4 mean in an PCIe Gen X4 NVME drive?

Max speed of PCIE for SSD m 2 pcie 4 0 in 3 0 slot 2 slots where at least one supports PCIe, it's worth considering your secondary slot for an SSD upgrade When combined with an NVMe SSD, PCIe will result in m2 slot types NVMe SSDs, including the KC3000 PCIe , the NV2 for smaller form factor devices and the DC1500M four-lane PCIe for mixed workloads Toshiba

m2 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