So I am helping a friend out, who has an old Alienware computer. It's the Aurora R2 using the RV30W motherboard. We recently replaced his graphics card with no issue to an MSI gtx 970, but having trouble figuring out what RAM is going to be compatible here. I gave him some old ram I had 2 4gb sticks (PGV38G1333ELK) but I could only get them to work by themselves, they would not work with the old ram in the other slots (it came with 2 sticks of 2gb, and 2 sticks of 1gb for total of 6gb when originally bought). I know nothing about the old sticks, they aren't labeled well and I can't seem to find a google answer. Now I do know that the RV30W has a max of 16gb ram capacity, so can anyone point me in the direction of 2 more 4gb sticks that will work with the 2 I already installed?