The MSI MEG Z890 ACE is the objective winner of this comparison, securing a lead in eight of the thirteen evaluated specifications. Its most significant advantage over the competition is its USB Type-C connectivity, which offers a 200% improvement in that specific category. While the ASRock H670 Steel Legend manages to outperform the MSI board in two areas, including a 100% advantage in PCIe x1 slot availability, it falls behind in the majority of the measured technical metrics.

Users who prioritize modern peripheral connectivity and high-end interface standards should choose the MSI MEG Z890 ACE for their build. Conversely, the ASRock H670 Steel Legend is the better option for those who specifically require a higher density of PCIe x1 slots for expansion cards. Selecting between these two motherboards depends entirely on whether your workflow demands superior USB Type-C integration or a greater number of legacy-style PCIe expansion lanes.