I am planing to build a new PC, and the motherboard is gonna be Gigabyte GA-Z170-HD3 (DDR4 version). I plan to get 8 GB, and HX421C14FBK2/8 (2x4GB) is cheap in my country currently, and this was the one I planned. However, checking Gigabytes website, only HX421C14FBK4/16 (4x4GB) from Kingston modules shows to be compatible. Can't I really use HX421C14FBK2/8, even if modules are practiclly the same?