The Gigabyte X670E AORUS MASTER wins in 8 out of 14 comparable specs, with 4 ties. Its biggest advantage is M.2 Slots (100% better).
B550 AORUS PRO AC wins in 2 specs (PCIe x1 Slots: 100% better).
Recommendation
Choose X670E AORUS MASTER if you want the best overall performance — especially m.2 slots.
Choose B550 AORUS PRO AC if pcie x1 slots matters more to you.
