jerry.seutter at pason.com
Thu Jan 22 21:00:56 GMT 2004
On Thu, Jan 22, 2004 at 12:42:44PM -0800, jw schultz wrote:
> On Thu, Jan 22, 2004 at 01:36:05PM -0700, Steve Sills wrote:
> > Well, it is running under SSH, that could slow it down i guess....
> Very easy to tell. If ssh is burning user-mode cpu time the
> encryption is a factor.
> It is very unlikely the encryption is having any affect on
> throughput. Unless you are on very old hardware the network
> is slower than the CPU and for rsync the disk latency likely
> makes it slower than the 10MBps network.
I will have to disagree with you on this point. It depends on your
definition of old hardware, I guess. I did some testing with a
400 MHz machine and found that it was able to transfer via ssh
at a rate of about 1.4 Megabytes/sec. That was with the default
cipher, which was... uh... 3DES? Extrapolating linearly, you
would need about 2.8 GHz to fill a 10 Megabyte/sec (100 megabit)
connection. This is assuming my machine is a typical 400MHz
In my situation I found that changing to the arcfour cipher (now
considered weak encryption) increased throughput to 2.7 Megabytes/sec.
For a secure but middle-speed cipher you can also try blowfish.
More information about the rsync