The ASRock H670 Steel Legend is the objective winner of this comparison, securing a higher number of superior specifications across the evaluated fields. While both motherboards share many identical features, the ASRock H670 Steel Legend provides the most significant hardware advantage by offering 50% more PCIe x1 slots than its counterpart. This expansion capability serves as the primary differentiator between the two boards, establishing the H670 model as the more versatile option for internal connectivity.

Users who prioritize additional expansion cards should choose the ASRock H670 Steel Legend for its superior PCIe x1 slot count. Conversely, the ASRock B550 Steel Legend is the better selection for builders who require extensive storage configurations, as it provides a 50% advantage in available SATA ports. Selecting between these two components depends entirely on whether your specific build requirements lean toward secondary peripheral expansion or a higher capacity for traditional hard drives and solid-state storage.