Asus Q405UA RAM Upgrade

milesuy · February 25, 2022

I already have a 1x16GB 2666MHz RAM module in stock, and I am planning to upgrade a friend's laptop by adding the aforementioned RAM module. The laptop already has an 8GB RAM soldered into the mainboard.

On Crucial's Upgrade page, it says that the laptop only has an 8GB non-removable memory, but I found an article and a disassembly video that shows that the laptop has a free RAM slot.

The article also mentioned the following:

Quote

Finally, you can access the memory expansion slot and upgrade RAM if necessary.
You can add up to 8GB 2400MHz DDR4 SDRAM memory module in the open slot.

Questions:

What would happen if I install more than the laptop's supported RAM capacity?
Will the laptop work if I add a RAM that has a higher speed (2666MHz)?

milesuy · March 5, 2022

Looks like I'll answer my own question.

I tried to install a Crucial 16GB 2666MHz DDR4 SODIMM module on the Asus Q405UA and it worked, so the laptop now has 24GB RAM, 8GB soldered + 16GB module.

The part number of the 16GB RAM module is "CT16G4SFD8266.C16FD1". The exact model of the laptop is ASUS Q405UA-BI5T5.

On 2/25/2022 at 9:27 AM, milesuy said:

Will the laptop work if I add a RAM that has a higher speed (2666MHz)?

It will run at the same speed as the slowest RAM.

nirlicnick · June 30, 2023

Okay so a lot of ASUS laptops do this. They have around 8GB of RAM on the motherboard. I have a Q543UX and there is one RAM port. but it has 16GB of RAM. The RAM slot has one 8GB stick too. I was also curious if I could just ignore the RAM Specs and just use the port. I plan on trying to just throw as much in there as possible and see how an benchmarks go.

I have looked around for this issue/thing for a while and it seems like most ASUS laptops aren't marketed as having the internal RAM on the board. Most places will just say that it has 16GB with 2 ports, 16GB with 1 port, or 8GB with 1 port. Never have I seen that it written or shown as it really is.

I plan on making a small video showing the tests and going over the who deal. I know this thread is dead but ill leave the link here as Google found this thread for me on the first page.