Both Dell specifications and Crucial say that your system accepts maximum of 16 GB of DDR3L RAM at 1600 MHz. If you have a single 8 GB stick in one slot and the other slot is empty, you could try to add a second 8 GB stick of the same specifications. It may work. But, sometimes mismatched RAM brands/models may not play well together, which is why a matched pair is recommended. I would try a single 8 GB addition first, provided that you can return it if it doesn't work. Performance RAM, like Corsair Vengeance or Kingston Fury, is unlikely to work. You need RAM that matches your current RAM's latency, likely CL=11. Crucial is highly compatible with Dell systems, and likely Hynix and Samsung, as Dell often includes them with its systems. I recently bought a relatively unknown brand, Kuesuny, through Amazon for much less than the price of a big brand name, and I'm happy with it. I ran memory tests for a couple of days to thoroughly test the RAM when I first installed it. It performs well and saved me money. Whenever touching components or working inside a computer, wear a grounded wrist strap, also called anti-static wrist strap, ESD wrist strap, or ground bracelet. It's a cheap and sensible precaution. Rest the laptop on an anti-static mat or at least a reasonable alternative such as corrugated cardboard. (Repeatedly touching a metal case part is not sufficient mitigation with modern components.)
My Alienware 17 R2 has 1x8gb of ram and I want to upgrade to 2x16gb. But can I just add another stick of ram to the default Dell ram or must they be the same brand?
17 R2, ram upgrade specifications