Best Slot for 16GB RAM Upgrade for Optimal Performance in a Laptop?

[Ambady]

Hi ,
I have a laptop with two RAM slots. One of the slots is currently occupied by a 4GB DDR4-2400 SK Hynix stick. I recently bought a 16GB DDR4-2400 SK Hynix RAM to upgrade.
My question is: should I place the 16GB stick in Slot 1 or Slot 2 when paired with the 4GB for the best performance, or does it not make a difference?

I know this might seem like a basic or unnecessary question to some, but I’m asking out of genuine passion for learning and getting the most out of my machine. I just want to make sure I’m doing it right and getting the best performance possible. Any help would be greatly appreciated!
Thanks so much for your time and patience!

:::::::: my system specs :::::::::
Laptop: Acer Aspire 3 A315-41-R45R
Processor Name: AMD Ryzen 5 2500U
Motherboard Model: RR Metapod_RR
OS: Windows 10 Home Single Language (x64) Build 19045.5011 (22H2)

[David (PassMark)]

Best performance would be with two matched sticks. This would allow dual channel mode to be used.
So if the laptop supports it, get 2 x 16GB.

[Ambady]

It's already purchased. Could you please tell me the slot it's favourable. I I learn somewhere that when using different size memory together smaller one will fill first then after the larger one. Do you know anything support for my situation. It's not possible to buy another 16GB do you my situation

[David (PassMark)]

It's already purchased

Yes, and I am suggesting you buy another identical module. Anything else is sub-optimal.

Timings are likely to be different between the two sticks you currently have. So we can't say which stick might be faster. We also don't know the wiring on the Acer Aspire 3 A315-41-R45R.
Only thing we can say if follow suggestions in the user's guide. But that will also likely suggest using two identical sticks.