Syncthing is running on a Mac mini (2018) with 3.2 GHz 6-Core Intel Core i7 and 32 GB 2667 MHz DDR4. It’s connected via ethernet to a Synology ds-418play with 2gb memory and ~ 24tb of WD Red (spinning) drives. There was approx 2tb of data in the cloud (and a local folder on the synology with a lot of folders and probably hundreds of GBs maybe a TB of data.)
Scanning was blocking a MacOS security update (amongst other things) and I decided after watching it slowly making progress over many many days to just take an extreme step. I deleted a bunch of the backed up data in the cloud and moved local files to another folder.
This had the desired outcome of significantly speeding up scanning (it more or less become a several minute exercise.) My main obj here is to just migrate Syncthing to running on my Mac so I can consider updating my Synology (which will sadly prevent me from running Syncthing on it - which would be my preferred local host.) I’ll see how this runs for awhile before committing to this approach. I can’t determine precisely why Syncthing runs more efficiently on my synology as the Mac mini isn’t that old. I def could be wrong but I assume the network transport layer is causing the majority of the lag. While I’ve setup the synology to use both nics as one I doubt that is doing much good here.
As an aside I did try the config proposals (thanks for linking to them) before making these changes but they seemed to have no noticeable impact. So, I reverted to the defaults for now. I am kinda curious how this will run over time…
I do hope someone from the community is inspired to make a package that runs on the latest syno update. 