I'm looking to boost the RAM in my Dell Inspiron 5491 2-in-1 laptop, which currently has 8GB of factory-installed RAM (SODIMM DDR4 2666 MT/s). It also has a 500GB SSD and an Intel i7 processor. My laptop can support up to 32GB of RAM with a total of 2 slots (1 slot is currently open). I can't decide whether to buy a single 16GB DDR4 2666 MT/s module to go with my existing 8GB for a total of 24GB, or if I should replace the 8GB module with two 16GB DDR4 2666 MT/s sticks for a 32GB configuration. Additionally, can I use RAM that operates at 3200 MT/s, or do I need to stick with 2666 MT/s? I noticed my DRAM frequency was measured at 1330 Hz using CPUZ.
1 Answer
You can mix and match RAM speeds, but your laptop will only run them at the speed of the slowest stick. Since you already have 2666 MT/s RAM, I’d recommend either sticking with that speed or using faster memory that will downclock to match. So, if you go with a 16GB 2666 MT/s stick alongside your 8GB, it'll work just fine. If you opt for the two 16GB 3200 MT/s modules, they’d also just run at 2666 MT/s, but you’d get the benefit of higher capacity.

So just to clarify, if I use 3200 MT/s RAM, it won't hurt anything, but I'll just miss out on the faster speeds, right?