The MSI MEG Z890 ACE is the objective winner of this comparison, securing victory in eight out of thirteen evaluated specifications. Its most impactful advantage is the USB Type-C connectivity, which offers a 200% improvement over the alternative. While the ASRock B550 Steel Legend holds its own in specific areas, the MSI MEG Z890 ACE provides a more robust feature set across the majority of the measured technical categories.

Users who prioritize modern peripheral connectivity should choose the MSI MEG Z890 ACE for its superior USB Type-C capacity. Conversely, the ASRock B550 Steel Legend is the better option for builders who require a higher density of expansion cards, as it provides a 100% advantage in available PCIe x1 slots. Selecting between these two motherboards depends entirely on whether your specific build requires more high-speed external ports or additional internal expansion slots.