Slightly OT - SFTP versus FTP speeds

[Rashkae]

Steve Flynn wrote:
> On Thu, Sep 24, 2009 at 11:06 AM, Steve Flynn <anothermindbomb at gmail.com> wrote:
>> I know many of you use SSH to securely leap from machine to machine.
>>
>> How many of you utilise SFTP and vanilla FTP though? If you do, what
>> kind of speed difference do you witness in throughput?
>>
>> I ask because the current environment I'm working in (a clients site)
>> is seeing quite large differences in throughput between two machines
>> (on in the UK, another in the states). The circuit connecting the two
>> is a private circuit, no other traffic on it during our testing
>> periods. I am seeing a 100Mb file or Lorem Ipsum text being
>> transferred at up to 4.4Mb/s (which is about as fast as we'll get it
>> to move as the slowest part of the circuit is about 5Mb/s.
>>
> 
> Damn - hit send accidentally.
> 
> As I was about to say, vanilla FTP hits around 4.4Mb/s.
> 
> The same file, over the same circuit when being sent via SFTP
> (Blowfish encryption, compression off) manages a rather disappointing
> 300 K/s.
> 
> I'm well aware that encrpytion is going to cause a reduction in
> throughput but I'm having a hard time convincing the network engineers
> that a drop from 4.5 meg per second to 300 K per second is
> considerably more than I would expect.
> 
> Anyone out there got similar results I can compare against.


That's way abnormal.  I've seem some very wild varience in speed between
different SSH clients (you didn't specify which you were using) but
nothing that would account for that kind of speed penalty.  There have
been some reports of ISP throttling encrypted traffic in their P2P
fighting attempts, but again, this is a bit extreme.  (ps, you should
probably leave encryption on, in any case.)


I would suggest trying Filezilla on Windows as the client