[Borgbackup] remove ssh or via SMB?

[Steve Schow]

I have recently ran some tests and notice that I got 25% faster performance by sending data from borg to a remote machine via SMB share vs using SSH remote tunnel.  I also note that CPU performance on the source machine is substantially worse with the SSH tunnel, as the SSH process itself imposes signficant overhead in addition to the borg process.

Can anyone comment about why this might be, how it might be improved or any particular reasons why the SSH tunnel would be preferable to saving the archive over SMB networking?

Test scenario:

Borg 1.1
  source machine:  readynas 6.8.0
  dest machine:      OSX 10.9.5
They are connected via gigabit switch

With SMB, getting about 20MB/sec.  Via SSH getting 15MB/sec

readynas is mounting SMB share located on mac computer for SMB case.
readynas is sending to mac via SSH, where borg comes up in server mode.

In general, the NAS is capable of much more than 20MB/sec, as is the mac, so I am also wondering what else I might be able to do to speed things up.  Ought to be able to get 50MB/sec