4x4 or 8x4?

[Frostbitte]

I currently have two brand new 4gb RAMs, and only two slots on my MB. But one of my older computers I found out has a 8gb stick probably a few years old. They are all the same speed, 1600, since I'm cheap (unrelated how much does speed help?)

But will it be okay and better if I do 8gb and 4gb, even if the 8gb is older? Or should I stick with my two 4gb's?

Thank you so much

 

[Tradesman1]

Since you have them give them a try, would put the 8GB in slot cloeset to CPU and 4 in the farthest Let us know what it does, if problems let us know mobo model, CPU and model #s of the sticks of DRAM