PCIe vs NVMe: Are They the Same?

Yes, the PCIe cards can indeed be installed in PCIe slots and vis-a-vis as the PCI interface is designed as forward and backwards-compatible However,

Both PCIe and slots can be configured with x1, x2, x4, x8, and x16 lanes, but PCIe slots have a higher transfer rate per lane and

pcie x1 slot function Will PCIe graphics cards be compatible with a PCIe slots? If yes, what about the performance? 8 41K Xristo replied

pcie gen 4 in gen 3 slot PCIe 's throughput is 1GB per second per lane, providing an overall data transfer rate or bandwidth of up to 32GBs total PCIe doubles