SFTP download speed 20% of line speed

[sbquint]

Running:
Syncback Pro 5.17.00
Vista 64 fully upp'ed

I am aware that:
B=byte
b=bit

I have several hundred Gigabytes to download.

DSLreports Speedtest report that my cable connection is running at anywhere from 8 to 16 Mbps, which is, in Bytes, is 1000 to 2000 KB.

Syncback Pro using SFTP only downloads at between 150 to 500 KB, and fluctuates.

Is there anything I can do to speed these downloads up?

I tried multiple profiles on another SFTP host and ended up getting random errors. I never got the errors when I ran only one profile at a time. The errors were usually to delete a local directory and files. If I re-ran the profiles one-by-one Syncback would not want to delete the local directory and files, so it really appeared like something was dropped file list data somewhere. Because of all that, I am afraid to try multiple profiles again.

I searched a little and one guy said he set a high limit for (S)FTP speed in Syncback and that made it run faster. Sounds dubious, and may be just a coincidence.

One guy said he just uses HTTP downloads and starts a bunch (like 20). Yeah, uhm, not an option for 6700 files, and I need to backup, not just pull them down once.

In another place, someone said the Syncback developers were considering multiple threading. Any progress?

And someone said SFTP is always slower. But I doubt that could explain running at only 20%.

Interestinly, I tried Filezilla, and get a constant 100 KB, which is much lower than the fluctuating speed of SyncbackPro of 150 - 500 KB. That smells like a windowing thing -- Syncback does better windowing?

... stand by ...

Okay, while typing this post I decided to try creating a second profile. The main one was downloading around 350 KB. I started up the second one, and now it is also running at 350. This shows that the first profile is not using all the bandwidth that is available.

Now, with the two profiles I've doubled my download speed, but this is a poor solution, really. I won't know if the random errors will happen until I run it a few days. And also, like I said, my line speed is 1000 - 2000, so I would need to set up and juggle 4 or 5 profiles. Definitely not ideal.

Is SFTP a polite protocol or something (low priority)? Would FTPS be any faster, or even (gasp!) FTP, or WebDAV? I definitely want encrypted comms, and I want Syncback's excellent brain to keep track of new files and stuff.

Is there any way for me to speed this up in one profile? Upgrade? Settings? VPN tunnel? SSH tunnel? Go to Windows 7?

[sbquint]

any other suggestions?

[Dave Wilkins]

There's been no progress on multi-threading, no. I gather it's still on the ideas list, but no clue 'whereabouts' (how far up/down).

You mentioned several possible alternatives (such as FTPS) but don't say whether you tried it/them. All I can suggest is 'experiment'. Others are free to pose suggestions, obviously.

Bear in mind using multiple profiles (if you do) needs you to be very careful setting the scope of each profile so there is no overlap (otherwise they'll fight over any 'joint' files')

[sbquint]

Well, I really don't have a bunch of hours to experiment. So I'll just keep using multiple profiles. Once I get the 300 gigs downloaded, I can probably get by with just one profile for the ongoing backups.

So Syncback isn't perfect, but it's definitely the best thing out there, and I've searched. Syncback is awesome.

[sbquint]

Odd ... my internet service went crappy for a few days, and now it's back to normal for a couple weeks, however Syncback is blisteringly fast now -- like 20 mbps ! Yeah, full line speed on one profile.

I guess the cable company did an upgrade, or changed something. Regular stuff, downloads, etc. is the same speed, but syncbackpro screams. It used to hover around 2 - 3 mbps per profile. Maybe they un-throttled SFTP/FTP, or added new fibers to my destination.

Awesome. No more need to juggle multiple profiles for me anymore.