"Although this particular M.2 slot, found on the underside of the Aorus Pro AX, is a PCIe 3.0 one. Still, 3GB/s is hardly sluggish is it."
From the manual:
1 x M.2 connector (M2B_SB on the back of the motherboard, integrated in the Chipset, supporting Socket 3, M key, type 2260/2280 SSDs:
- Supporting SATA and PCIe 4.0 x4/x2 SSDs