RX 570 run at PCI-e x4 instead of x16

PCI Express Expansion · Five PCIe Gen 4 x16 Slots One PCIe x16 Slot for Target Cable Adapter; Four PCIe x16 Slots for Add-in Card · ATX

Physically yes, the slot connector for an x4 is generally smaller and PCIe is designed that smaller cards can occupy larger slots if needed

pcieslot You can put anything smaller than the slot in just fine It's the PCI-e bracket screw that really holds things into place I'd get the newest

pcie m2 slot Expansion slots, 1×PCI-E x16; 1×PCI-E x16 ; 1×PCI-E x1 ; Storage devices, 1× PCI-E x4; 3× PCI-E x4; 8×SATA 6