There is actually something wrong with how docker on Synology reports RAM usage. I am running 3 nodes on my Synology and it claims total RAM usage is about 3.6GB across the relevant containers. However, my total system RAM usage is 2.72GB atm, so that can’t possibly be true. If you click through to the details you find the actual numbers under the process tab. My biggest node is currently only using 40.7MB for the node and 9.5MB for the dashboard I keep open in tmux.
RAM usage really is negligible as long as your HDD’s can keep up. It can go up during busy times, but this is a node storing 15TB of data and it still only uses 40MB.