[Gllug] Observed speed of gigabit ethernet only about 1/4 or 1/5 of advertised

[Richard Jones]

On Sat, Jul 14, 2007 at 03:37:15PM +0100, Tethys wrote:
> Richard Jones writes:
> >I wonder if someone can suggest from the description below where the
> >weak point is likely to be in this setup.
> 
> You will rarely be able to use ssh at wire speeds, due to the encryption
> overheads at each end. I would have thought ttcp should be able to get
> there or thereabouts, though. Have you tested it with netcat?

My SSH calculation was wrong - it is in fact 22 MB/s * 8 (not * 10)
which gives 176 Mbps, about the same as ttcp in TCP mode.

For Netcat I also get 176 Mbps.  That seems to be the basic speed for
TCP, and around 195 Mbps for UDP.

So I'm definitely missing about 4/5ths of the advertised throughput
somewhere.

Rich.

-- 
Richard Jones
Red Hat
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