Saying it isn't utilized properly isn't really correct. The extra bandwidth just isn't being used. This is the case when using a discrete graphics card. When using an igpu, it would help quite a bit since ram is used as vram. If you check your ram usage when gaming, you are probably using it all up so the increase in ram will benefit you either way. You already have a 4gb stick, it makes no sense why you would go to a single 8gb.