Is there any benefit to putting a PCIe 4 SSD in a PCIe 3 slot?

Need to know what PCIe Gen are the two SSD slots for Acer Nitro 5 nvme gen 4 in gen 3 slot slot) In fact I've even successfully used a x4 adapter advertised as PCIe to run a Gen 4 drive at full speed in a PCIe slot: WD nvme pcie 40 in 30 slot Solved: Does installing gen4 NVMe SSD on PCIe 3 slot affect the speed? or should i buy 3 gen3 NVMe ssd? Please give me some advice

nvme and m2 slot difference 2 slots I'm looking to add 2 pcie gen 4 nvme SSDs I assume one drive will use one of the x16 lanes And the graphics card