Colin Johnston
SA
PSINET UK
On Fri, 5 Nov 1999 spamhater03@birch.crd.ge.com wrote:
> I have a Windows NT client talking to a Solaris server.
> The CLient has a 10 MB/s card, the server has a 10/100 MB card.
> Using the TCP_TCP_STREAM benchmark, we got two different results:
>
> Using a cross-over cable (no hub) we got a value of 8.77
>
>
> C:\netperf>netperf -Hdemo -l60 -v2
> TCP STREAM TEST to demo
> Recv Send Send
> Socket Socket Message Elapsed
> Size Size Size Time Throughput
> bytes bytes bytes secs. 10^6bits/sec
>
> 16384 8192 8192 60.00 8.77
>
>
>
> Adding a NDC SOHO 10/100 mb autosensing hub, the performance is now:
> C:\netperf>netperf -Hdemo -l60 -v2
> TCP STREAM TEST to demo
> Recv Send Send
> Socket Socket Message Elapsed
> Size Size Size Time Throughput
> bytes bytes bytes secs. 10^6bits/sec
>
> 16384 8192 8192 61.00 1.80
>
>
>
> Why would a hub degrade the performance so much?
> Is it the auto-sensing?
> This is a simple hub with one switch (uplink on/off).
>