Can I use a Gen 4 NVMe SSd in a Gen 2 slot?

Right now I have a Samsung 950 Pro 512 GB SSD on an adapter plugged into a Gen X8 slot I just tested it and I got 1,948 MBs read

2 Get the generation of the PCIe itself $ sudo lspci -vv -s 08 grep -w LnkCap LnkCap: Port

m2 pcie slot The ADATA LEGEND 960 PCIe SSD supports the latest Intel and AMD platforms and also meets the NVMe standard The LEGEND 960 supports PCIe and

m2 sata vs nvme slot Crucial P3 1TB PCIe Gen3 2280 NVMe SSD Save $ Crucial