How much overhead does SFTP incur?

[screw3d]

I have tried connecting to my server via both plain FTP and SFTP on Filezilla. On plain FTP, upload speed is about 200+kBps, but on SFTP, it drops to only about 80kBps.

Is there really such a significant hit or could there be a misconfiguration on the server? I think my webhost (site5) is using ProFTPd.

 

[Nothinman]

You have the overhead added by encryption which will mostly be CPU and possibly compression. If the line is slow and both CPUs can keep up compression might help more than hurt. If you think it might be CPU related try using blowfish encryption and no compression.

 

[screw3d]

Originally posted by: Nothinman
You have the overhead added by encryption which will mostly be CPU and possibly compression. If the line is slow and both CPUs can keep up compression might help more than hurt. If you think it might be CPU related try using blowfish encryption and no compression.

I am aware of why it has the overhead.. but it seems kinda high to me though 😕 I tried it over WinSCP and got roughly same speeds.

 

[Nothinman]

But do the hosts in question have the CPU power to keep up with the added encryption? I don't believe the actual network overhead is that high.

 

[screw3d]

Originally posted by: Nothinman
But do the hosts in question have the CPU power to keep up with the added encryption? I don't believe the actual network overhead is that high.

I'm not sure about that.. the server is a Dual P4 with HT but of course that doesn't say anything about the load. So you think the bottleneck is on the CPU?

 

[Nothinman]

Transferrering a file from a P4 3Ghz running Linux to another P4 3Ghz Win2K box using WinSCP with blowfish encryption and no compression on a 100Mb lan I can get ~3M/s.