Hi, I'm seeing similar issues when syncing large files. Speed goes up to reasonable level, then slows back down to zero, then picks back up again. Sometimes it pauses for some seconds while with "Nothing being transferred right now" in the Transfers tab, possibly before moving onto the next chunk. It's very inefficient as a result. The box sending the files is a Debian 7 64-bit host, reciever is Win 8. Also can you clarify whether Bt Sync uses multiple concurrent connections to transfer single large files? If not, when is this capability expected to be added? It would be a very useful feature for this software to have. Thanks, Bohdy.