Should I use mixed RAM and/or fill all RAM slots? [closed]

I want to upgrade my laptop's RAM. Currently, I have 16 GB (2x8 GB) RAM, and I want to upgrade it to 32 GB.

My computer has 4 RAM slots (SODIMM), 2 is already filled. In the internet, I've read that filling all 4 slots could cause performance issues and also using mixed RAMs (size, MHz, brand) is not a good idea.

The tech support guy from Dell recommended me to buy another 2x8 GB RAMs and install it but the RAMs I can buy from Dell's website are 2666 MHz and currently I have 2400 MHz RAMs.

I was thinking of buying another 16 GB and installing it in the 3rd slot but I have no idea what dual channeling is. People say it is really bad to use 3 slots.

As you see, I am really confused. What should I do to upgrade my device's RAM?

Thanks and stay safe.

2 Answers

In general, mixing RAM brands is usually fine, though there sometimes are weird incompatibilities so it's preferred to use the same brands.

Dual Channel is when any two sticks of RAM are inserted (so a 4gb stick and an 8gb stick together would be "4gb dual channel" because only 4gb are 'shared'). Dual channel configurations give you a nice performance boost, usually.

Then there is RAM speed. If you get 2666MHz RAM and you have 2400MHz RAM, the 2666MHz RAM should automatically run at the slower 2400MHz speed.

Use CPU-Z to check if you have dual rank RAM (which means you should probably leave one slot empty for each dual rank RAM stick).

If not, then I would go with what the Dell guy recommended, 2x8GB RAM from either the Dell site or somewhere else (like Crucial). Even if it is a higher speed, it should automatically run slower, and you get the dual channel performance.

You can fill and mix ram slots.however the slowest ram stick will be the one to dictate the speed through the ram portal.As Aman mentioned you run the risk of errors. Never heard of such a thing of bad idea when it comes to filling all 4 slots.I find that hard to believe. I use CPU-Z, but rely on Speecy , which can be found pretty much everywhere.Speecy gives a very good detail of slots,speeds, and a lot more then CPU-Z. Hope this helps.