I guess bt sync calculates hashes, but why is it so slow ? Aren't there faster methods to compule a hash ? I know subtitle downloaders use a fast hash methods, which might only read some bytes and use the file size as a hash parameter to avoid hash collisions. Anyway, this is a downer, I'm sure bt sync could do better than this, I'm sure there is something badly done underneath. Now bittorrent seems completely stuck at a small wav file, it doesn't index it or transfer it. Should I use syncthing instead ?