RAM Memory compatibility QNAP 469U

[konekto]

Greetings,
i have a question about memory compatibility on these nas servers.
Model of NAS that i want to upgrade with more system memory is 469U and has 1GB of RAM installed.
Based on online search i found that its using DD3 SODimm memory and that it has max of 3GB capacity with 1333Mhz max speed.

1. Is there anything to look for specific to match the installed out of the box memory compatibility wise?
2. Can you install 2x2GB and still get fully working system without issues?
3. Is there support for 4GB dimms - similiar as question above, if it has 3GB max memory, can you get it with installing only 1x4GB?
4. Is there a diffrence in number of chips on dimm, double sided, single sided, also do tiings play a role in system performance?
5. Can you combine original 1GB stick with another 2GB branded one, and what should you look for when matching it exept speed, voltage and timings?

I would appreciate if someone could give answer to any of the questions above, it would be of great help.

Thanks

[Gaudi]

Hi, I have a TS-469 Pro and have installed 2x 2GB DDR3 KVR1333D3S8S9/2G.
These modules work perfectly fine (more than 5 years in service now, soon to be replaced by a new NAS), though as you may know, the unit addresses only 3gb.
I formerly used only one of these modules with the original 1gb stick and it worked without issues.
So no need to swap the original 1gb, but I did it anyway.

I am unaware if the motherboard can support a 4 gb module, but being 2gb DDR2 cheap, I would not spend any more than necessary.

Hope this information helps you.

[OneCD]

My TS-569 Pro only supported 3GB while QTS was installed. When I dumped QTS and installed Debian, I was able to access 4GB. So, it looks like an artificial limitation of QTS.