[plug] file transfer performance linux/windows and filezilla

[Craig Ringer]

On Tue, 2004-05-11 at 23:04, Denis Brown wrote:

> a)   Set up /etc/ssh/ssh_config global config file to use blowfish as the
> standard algorithm on the two Linux machines previously used for testing.
> b)   Transferred an .iso file 650MBytes, same one I used earlier.
> c)   Transfer time with default cypher (3des???)  59 seconds
>      Transfer time with blowfish cypher  58 seconds
>      Transfer time with -c blowfish command line option, 58 seconds

Those are all pretty close to wire speed for 10/100 ethernet, yes?

> While the transfers were in progress I ssh'd in and ran "top" to examine
> the status quo.   In the case of transfer from slower machine to faster
> machine, ssh was running around 81% of cpu.

Yeah. blowfish will only be faster if 3des maxes the CPU - it's faster
because it's less heavy on the CPU. Clearly, your systems are up to
doing 3des at 10/100 ethernet speeds.

> Correct me if I'm wrong but the above would seem to vindicate the network.
> So begs the question why ssh (or Debian's implementaion of ssh???) is so
> slow.

?!?

I assume you're referring to a different ssh than the one you tested
with above? 11 megabytes per second is mighty fast for 10/100 ethernet.

The transfer to/from WinNT doing only a few hundred KB/s would
definitely qualify as slow. Are you seeing similar symptoms between two
linux boxes as well?

Craig Ringer