Are you running an official build?

This page indicates that your usage should be around 80 megs (with the gui closed): https://forum.syncthing.net/t/huge-ram-usage-2gb-on-synology... and that an unofficial NAS-specific build had a problem with high ram usage.

I always ran official builds, my NAS are just standard x86 servers. Last time I checked was January 2015:

https://github.com/syncthing/syncthing/issues/468#issuecomme...

Since that bug was closed with no solution I'm not too hopeful but maybe I should try it again.

If you can reproduce the issue, be sure to post on the forum so we can figure out the cause.

See the bug report at the time. It was closed without being fixed and it was 100% reproducible. Maybe it's fixed now but no one was too worried about it then and I saw similar reports on the forums for a while before I lost interest. I should either try syncthing again or finally test infinit completely. This is the last piece of the puzzle I'm missing to have a fully workable personal data management solution that allows me to bring up a completely new laptop with my full config and data with just a clean Ubuntu install and a few commands.