ven98 Pathfinder

Unfortunately, from the information that I have, this PC has one regular Type C 3.1(Gen 2), which isn't thunderbolt. 

If an option to change the refresh rate doesn't exist in the OSD, you can try creating a custom resolution with a higher than 144Hz refresh rate from nvidia control panel or AMD adrenaline(depending on your GPU). I checked the monitor and it isn't shown or advertised as overclockable.

To clarify just in case, the laptop has 2 ports for storage, one is with M.2 interface(only for M.2 SSDs), while the other is SATA 3, which supports 2.5inch drives. If your laptop comes with 1TB HDD already, you will have to replace with the new drive.

Can you post the full model of your device(e.g AN515-42-AB12)?

You can try performing the instructions from the link below: https://acer--tst.custhelp.com/app/answers/detail/a_id/34843/~/acer-internal-battery-reset I suspect that could be a problem with the battery or possibly some other hardware fault, that can't be fixed without sending it to the service centre, unfortunately. About…

The max supported frequency is 2400MHz. If you install anything higher, it will be capped at 2400MHz.

The maximum amount of RAM you can have is 32GB(2x16GB). If you would like to know the maximum supported frequency post the name of the CPU that the device has. To check whether there is a single 16GB or two 8GB modules, you can use HWiNFO.

What is the name of the GPU that your device has?

There is 1 year international warranty, but it is not valid in the country you are resident in. For example, if you are on a holiday in lets say France and the laptop broke, you would be able to send it for warranty repair.

What games do you play? Try reducing the graphics settings a bit.

Have you tried the solution I provided earlier?

Have you checked what the battery percentage is, while you are gaming and the device is plugged in?

Then, that means you have to reduce the graphics settings a bit. I am not very familiar with how image rendering works, but I assume that, as you are not moving the GPU renders the same frame over and over again, which is much easier than rendering a new frame every time as you are moving. 

The chipset doesn't support memory overclocking, which means even with unlocked BIOS it won't work.

Try uninstalling the graphics driver with DDU in safe mode and install the latest one from Nvidia. If the newest driver doesn't work, you can try with older version. By the way, does the fps drop still occur if you rest on one place without moving?

You can check the temperatures from NitroSense. If it doesn't rise above 90C for the CPU and 85C for the GPU, then it is fine.

Temperature is not the issue. Do the fps drops occur in every game? If yes you can try removing the graphics driver with DDU in safe mode and then install it again.

I don't think 8GB RAM is the problem here, as CS GO isn't heavy on RAM. Just in case, can you show the RAM usage, while playing the game and I would suggest you to turn down the graphics if you haven't already. Please post a picture of the CPU and GPU temperatures, during a gaming session(at least 15 minutes after you…

Download HWiNFO or use Predator Sense and check the temperature of the CPU and GPU(please report the temperatures back here), as @xapim mentioned. Many users experience issues with fps drops, because of throttling.

Is the HDD that you currently have the only drive in your system? If yes, then replacing it with another drive wouldn't be an issue(I don't see a reason why it wouldn't in the first place).