I'm trying to backup a huge tar archive (150GB) from a root server (Debian Wheezy) to my local storage server (Cygwin). Speedtests with the root server give me about 100 - 120 MB/s download rate and the local server has a 100 Mbit/s connection that gives me about 10 - 12 MB/s both constantly.
However when I start pushing the file over SSH/SCP/RSYNC to my local server I only get about 2,5MB/s. The strange thing is: when I simultanously start another SSH transfer the throughput increases to 5MB/s, third one 7,5MB/s to the full capacity of the connection.
So my question: is it possible with the standard OpenSSH software to create a multithreaded TCP stream for example 10 connections to transfer one single file in a single command?
Or do you have any other hints how to efficiently use the connection?