The MSI MPG X870E CARBON WIFI is the objective winner, securing victory in ten out of thirteen comparable specifications. Its most impactful advantage is a 300% increase in maximum memory capacity compared to the Gigabyte B660M DS3H DDR4. While the latter holds a 100% advantage in the number of PCIe x1 slots, the former dominates the overall feature set, providing significantly higher headroom for system memory configurations and modern connectivity requirements.

Users prioritizing high-capacity memory support and advanced platform features should choose the MSI MPG X870E CARBON WIFI for their build. Conversely, the Gigabyte B660M DS3H DDR4 is the appropriate selection for users who specifically require a higher quantity of PCIe x1 slots for their expansion needs. Selecting between these two motherboards depends entirely on whether your workflow demands superior memory density or a greater number of specific peripheral expansion interfaces.