Question - PCIE 3.0 x8 into a PCIE 4.0 x4
That means a PCIe 4.0 Device in a PCIe 3.0 slot will work. However, it will be limited to operating at the max transfer rate of the PCIe 3.0 slot.
AM5 Motherboards with dual x16 (x8/x8) PCIe slots
Why have all the AM5 mobos lost PCIe slots in favor of marshmallow fluff options I’ll never use? I would like at a minimum one 4.0 x16 and two 3.0 x8 without having to downgrade the primary PCIe slot.
Can You Use a PCIe 4.0 SSD On Your Existing Motherboard?
The short and simple answer to your question of whether you can use a PCIe 4.0 SSD on your existing motherboard is a yes! You can use the PCIe 4.0 SSD on any.
What GPU can my motherboard support?: how to check GPU and motherboard ...
Can I Install a PCIe 3.0 Compatible GPU on a PCIe 2.0 Slot?