When reading the attach link (as an example) https://www.asrock.com/mb/Intel/Z170M Pro4S/index.us.asp#Memory I am a bit confused. As an example if you look at DDR4 Corsair 2800 4GB CMK16GX4M4A2800C16R SS 2 pcs. it would seem to mean 2 pcs of 4gb memory, or 8gb. However, when I search the memory module number, it shows it is 4 pcs of 4gb memory or 16gb. How can both be right?