Syncing partial files possible? (EU-->Asia)

Hey guys,

I would Syncthing recommended a couple of times, and I’m looking into it now.

To me it’s not clear if a Synthing client can take a partial file and instantly seed it further. Does this work or do the files need to be complete?

My weird use case - maybe you have an idea

I am a Vlogger and want to send 10GB 3 times per week from Europe to Vietnam where my editor is. Thoughts so far:

  • I could use bittorrent and seed it with a couple of local clients who then all upload to Vietnam
  • the connections from VN to outside are limited, so I though having multiple streams come through would be a good idea.
  • The files could be downloaded partially to different clients in Vietnam and then synced amongst them.

–> Does this work with Syncthing as well?

Is this idea stupid? Should I go rather with Dropbox or so?

Thanks a lot
Till from Sofia
(Yes, I am googling for this topic 2 days already with little help)

This should work fine. You’ll probably get best performance having a cluster of several machines both in and outside of Vietnam. They might share the pieces with each other faster than over the international border, and hence cooperate.

Thanks, Jakob! Alright, I just ordered a VPS inside Vietnam. I’ll see how things work out.

So, in short: yes: every tiny part of the whole data gets reseeded immediately?!

Not every part, there are some heuristics which don’t apply (such as small files) and not immediately (the updates of stuff available is sent once every 10s or so)

Thanks for the clarification. Yes, that’s not an issue at all.

My concern was that IF I send an (let’say) video interview of 4GB file size, it’d continue leeching/seeding from multiple sources at the same time. This looks like the right tool now.

With files there is an option about the order in which their are sent/pulled (?), and the default (random) makes sure that clients get different content first. Here it is just about a single big file though - so how is block order handled?

As it stands now it’s random, which is not ideal in a 1 to 1 scenario.

Hey guys,

I ran a test overnight. I’m still blown away.


  1. I need to upload 10GB / day to Vietnam (to my Vlog editor)
  2. I got a VPS in Vietnam and SCP’d 2.65 GB. It took 11h 40min. --> 3.8 MB/min or 4.4h for 1GB

Now with Syncthing:

  1. used my local computer as source for a 1GB file
  2. used another VPS as a third node in the US
  3. connected all 3 nodes together, dropped a 1GB file.

It looks like I more than doubled the upload speed by just switching from SCP to Syncthing and using another node. It took pretty much 51min for 1GB file.

Question: do I read the screenshot correctly? Did the file complete on the Vietnamese node at 21:20?

Is the upload speed on the right box (in the greyed area) the MEAN upload speed?

If this is true, this just solved my problem. Thanks so much for making this project!!

It’s emwa over some small window (10s or so).

I wouldn’t trust the log so much and would actually verify when its done. Also I’d double check how much the US node (intermediate) has uploaded.