Can I Use a PCIe 3.0 Card in a 2.0 Slot? - PC Guide 101
A PCIe 4.0 NVMe SSD will work in a PCIe 3.0 M.2 motherboard slot at PCIe 3.0 speeds.
PCIE 4.0 x8 on PCIE 3.0 x16 slot - Graphics Cards
1 cổng giao tiếp PCIe 4.0/3.0 x16 slot và 1 PCIe 3.0 x16 slot để trang bị cho card đồ hoạ rời kết nối tốc độ cao. 1 cổng M.2 22110 PCIe 4.0, 1 cổng M.2 22110 ...
graphics card - What exactly does the spec “PCIe 3.0 x16 slot ...
However, if your computer is equipped with PCIe 3.0 slots on the motherboard, then we recommend you choose the PCIe 3.0 SSD, instead of the PCIe 4.0 SSD.