Hi! I currently have 2x4gb DDR4 2800 installed, and I am planning to upgrade. My question is should I buy another set of the 2x4 I have to make it 4x4gb for the 16 gigs or go for a 2x8gb ddr4 set, which would be almost double the price? I am asking this due to the fact that I have heard that 2x8 is better. Many thanks!