How to determine from command line if NVMe slot is gen 3 or gen 4?

vs NVMe vs vs SSDs nvme in pcie slot 2 connector is a miniaturised x4 PCIe slot All devices are x4 or less lanes PCIe devices Don't matter if the adapter PCB physically fits a nvme gen 4 in gen 3 slot 2 slot and supports PCIe SSDs Most modern motherboards support this feature, some older boards had an slot but it was only able to connect to the SATA bus

nvme pcie 40 in 30 slot Enjoy extremely fast transfer speeds via PCIe lanes · Includes a heatsink and thermal padding · SSD bus interface: NVMe · SSD form factor: M · PCI Express