Memory upgrade on Synology DS1817?

[NC Enquiries]

I followed your guide and saw that my used swap memory has a value of 360Mb and should be 0 like stated (in your guide, you are at 4Kb).

So I guess I should upgrade my memory in my NAS, I received errors that I had not enough ressources to play some files on my plex server, so I guess this is related.

I have the DS1817 unchanged, what maximum memory is supported officially and unoficially (can I have 16 Gb on that model) and which memory modules I should get.

Thanks a lot!