can i put a pcie 4.0 in a 3.0 slot: Can I Use a PCIe 3.0 Card in a 2.0 Slot? - PC Guide 101. Will PCIe 3.0 x4 10Gbe NIC Work in PCIe 3.0x1 Bandwidth?. Can You Use a PCIe 4.0 SSD On Your Existing Motherboard?.
I tested PCIe 3.0 x4 10Gbe NIC in a PCIe 3.0 x1
slot, and here's my thoughts and results.
Can I Put a 4.0 NVMe in a 3.0 Slot? ... You can install a faster NVMe M.2 2230 SSD supporting the PCIe 4.0 standard into an older motherboard slot that only supports the PCIe 3.0 specification.