Yes, you can use both 4GB and 8GB simultaneously.
Yes, you can use both 4GB and 8GB simultaneously.
Yes, it's feasible to use different RAM sizes on the same motherboard. Your Asus ROG STRIX H370-F supports dual 4GB modules, and the motherboard you mentioned is compatible with that setup. You can pair your Crucial BLS4G4D26BFSB8FB 2x4GB with the Corsair Vengeance LPX 2x8GB RAM, ensuring proper compatibility. The CPU and GPU specs also align with future upgrades. Let me know if you need further guidance.