How to choose the right RAM for a laptop?

Question

RAM

There is a laptop with 4GB of memory and linux mint x64. There is a need for more memory, preferably 16GB. I started researching this on the internet. I found out that not every memory is suitable, and the laptop allegedly won’t pull more than 8GB ( characteristics )
. However, in the store, the seller, after demonstrating the price list, refused to do anything under the pretext of "what if it burns out?". Therefore, I want to learn here from those who have already updated the RAM in their laptops:
1) how to know exactly what kind of memory with what characteristics to take? I know that I have DDR3 SODIMM 1066 MHz, the problem is that there are no large volume memory sticks with the same frequency for sale. What happens if you set the bar with a higher frequency? smaller?
2) is it true that more than 8GB can not be installed? I saw a lot of messages from people who managed to put 16GB in the same scenario. Where does the 8GB limit come from and should I take it into account?
3) Is it true that something can burn out in a laptop or the seller lied?
4) let's say the goal is to reach 8GB of memory in total. Is it true that if you put two 4GB sticks instead of one 8GB stick, then there will be an increase in speed? The laptop has only two slots for memory modules.
I perfectly understand that everything can be googled, but the problem is that there are a lot of conflicting articles on the Internet, often written by SEOs who don’t understand the material at all, so I ask you not to send it to Google.

Answer 1

DDR3 SODIMM 1066MHz

The main ambush of the chipset is the memory bitness. That is, the chipset will not see memory with a larger capacity per chip. You seem to need - 16 tablets 256Mx8bits.
Ambush two. 1066 means it has less timings (delays) - 9-9-9-28
Now they mainly sell 1600 MHz - 11-11-11-28 and it's not a fact that it will start at 1066 with lower timings - 9-9-9- 28
Before buying, you must find a PDF from the manufacturer with a specification. The descriptions in stores may be nonsense. In this PDF, in particular, it can be written what is wired into the SPD at 1066Mhz.
The third ambush is voltage. There are still on sale from 1.2V to 1.65V. How the laptop gives out voltage, separately by slots or equally, no one knows for sure. That is, find out your voltage.
You need to tame yourself to pull out the battery and everything will be in order.
The most correct option is to sell / donate / throw away 4GB and buy paired 4 + 4 or 8 + 8.
Of course, you must take with a return.
(!!!) MemTest for the night without fail.
And the most important thing. If you want to achieve faster work, then first of all you need to change / add HDD to SDD . You will hardly notice the addition of RAM. But on an SSD, you just go nuts.

Answer 2

"Max. memory (depends on memory type) 8 GB"
processor specification: ark.intel.com/en/products/50178/Intel-Core-i3-380M...
from the same place: "Max. number of memory channels 2 ", that is, 2 bars will work a little faster (in practice, there will be no noticeable difference).
For stable operation, it is advisable to buy a bar similar to the one that costs, but you can take any other one, check it already in the laptop for compatibility, and if it fails, then return the plate itself to the store.