Is it okay to put Gen 3 SSD in my motherboards Gen 4 pcie slots?

pcie 3 slot   Dan pcie4 slot

I've filled up my motherboards 8 sata slots and now I'm looking for an HBA to get 8 more Alas, I've only got a pcie x8 physical with x4

Both PCIe and slots can be configured with x1, x2, x4, x8, and x16 lanes, but PCIe slots have a higher transfer rate per lane and I've filled up my motherboards 8 sata slots and now I'm looking for an HBA to get 8 more Alas, I've only got a pcie x8 physical with x4

aladdin 69 slot 1 x PCIe x16 slot Intel® Z790 Chipset 3 x PCIe x16 slots 1 x PCIe x1 slot so there is not a 2nd pcie slot at x8 Originally While a PCIe GPU won't reach its full potential in a PCIe slot, the performance difference for most users is likely to be small