The Gigabyte Z890 AORUS MASTER is the objective winner of this comparison, securing a lead in eleven out of fourteen evaluated specifications. Its most significant advantage is its maximum memory capacity, which is 300% higher than that of the alternative. This substantial increase in supported memory provides a clear technical superiority for the Gigabyte Z890 AORUS MASTER, establishing it as the more capable hardware option across the majority of the measured categories.

Users requiring extensive memory support should select the Gigabyte Z890 AORUS MASTER to leverage its primary capacity advantage. Conversely, the MSI PRO B660M-A WIFI DDR4 is the appropriate choice for those who prioritize expansion, as it offers a 100% advantage in the number of available PCIe x1 slots. Choosing between these two motherboards depends entirely on whether your specific build requirements prioritize high-density memory configurations or the additional connectivity provided by extra PCIe slots.