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

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Four NVMe SSD slots on a PCIe x16 card Silent operation Add your own ultra-fast SSDs for Mac, Windows, and Linux

nvme in pcie slot RTX 3070 for 3440x1440, and NVMe as PCIe card on the second x16 slot In other words, my GPU runs via PCIe x8 and I don't know of anything

nvme pcie 40 in 30 slot NVMe are pretty tiny slots for directly plugging in storage, and SATA was what came after IDE cables -PCIe tends to be