[geeks] Network Slowness

Caleb Shay caleb at webninja.com
Thu May 24 11:39:03 CDT 2007


On 5/24/07, Sridhar Ayengar <ploopster at gmail.com> wrote:
> Caleb Shay wrote:
> > On 5/24/07, Sridhar Ayengar <ploopster at gmail.com> wrote:
> >> Patrick Giagnocavo wrote:
> >
> >>> What protocol are you using for transfers?  SSH? FTP?
> >> OpenSSH SFTP using Blowfish ciphers.
> >>
> >
> > SSH has a massive overhead in processing, data size, and checksumming,
> > you can't use that for your testing.  For raw throughput, use
> > something like netcat
>
> Massive enough to slow a 1000Mbps connection to below 50Mbps?  No way.

Yes way.  That is why there are high-performance-networking patches
for openssh[0].  It's not network overhead, it's CPU time overhead.


[0] http://www.psc.edu/networking/projects/hpn-ssh/
-- 
"In wine there is wisdom. In bier there is strength. In water there is
bacteria."

--German Proverb



More information about the geeks mailing list