Can You Use a PCIe Express 3.0 Card In a 2.0 Slot?
Removable 2 Bay M.2 NVMe SSD to PCIe 4.0 x8 Mobile Rack Enclosure for PCI Express Slot (PCIe Bifurcation required) ... Note: To utilize an M.2, U.2, or U.3 NVMe SSD in a PCIe 16x slot, the motherboard or add-on card must support PCIe Bifurcation.
LAPTOP GAMING MSI GE66 RAIDER 10SFS 474VN RTX2070S 8 ...
2x M.2 SSD Combo (NVMe PCIe Gen3 x4 / SATA ) ... 2x M.2 SSD Combo slot (NVMe PCIe Gen3 / SATA).
How to Check Available RAM Slots in Windows 11 - GeeksforGeeks
Some NVMe SSDs in add-in card form can also be installed directly into a PCIe expansion slot on a motherboard. These cards are often referred to as "NVMe SSD add-in cards" or "NVMe PCIe expansion cards.".