Yes, the Asus TUF X570 supports full PCI 3.0 x 4 connectivity in both M.2 slots.
Yes, the Asus TUF X570 supports full PCI 3.0 x 4 connectivity in both M.2 slots.
The Asus TUF Gaming X570-Plus supports full PCI 3.0 x 4 connectivity in both M.2 slots or uses one PCI Express 3.0 x 4 for the CPU and the other via the chipset. If you're looking for consumer-grade boards with full PCI 3.0 x 4 slots, there are several options available.
The processor passes through the chipset, yet the component from the chipset can reach maximum speed for the M.2 slot.