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Re: network speed extremly slowed down

To: Stephen Hemminger <shemminger@xxxxxxxx>
Subject: Re: network speed extremly slowed down
From: Bernd Schubert <bernd.schubert@xxxxxxxxxxxxxxxxxxxxx>
Date: Mon, 14 Mar 2005 18:51:36 +0100
Cc: netdev@xxxxxxxxxxx
In-reply-to: <20050314092153.79ae93f1@dxpl.pdx.osdl.net>
References: <200503141745.08032.bernd.schubert@pci.uni-heidelberg.de> <20050314092153.79ae93f1@dxpl.pdx.osdl.net>
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On Monday 14 March 2005 18:21, Stephen Hemminger wrote:
> On Mon, 14 Mar 2005 17:45:06 +0100
>
> Bernd Schubert <bernd.schubert@xxxxxxxxxxxxxxxxxxxxx> wrote:
> > Hi,
> >
> > until one hour ago I thought this bug affects only 3com 3c509B cards. Now
> > we go on switching more and more systems from 2.4.X to 2.6.X and it seems
> > that many cards work much slower with 2.6.X
> >
> > with 2.4.27:
> > =========
> > bernd@pc-brenn bernd>nttcp -T hamilton2
> >      Bytes  Real s   CPU s Real-MBit/s  CPU-MBit/s   Calls  Real-C/s  
> > CPU-C/s l  8388608    0.72    0.02     92.7710   3355.4432    2048  
> > 2831.15  102400.0 1  8388608    0.73    0.04     92.0581   1864.3941   
> > 5783   7932.96  160661.2
> >
> > with 2.6.11.3:
> > ==========
> >
> > bernd@pc-brenn bernd>nttcp -T hamilton2
> >      Bytes  Real s   CPU s Real-MBit/s  CPU-MBit/s   Calls  Real-C/s  
> > CPU-C/s l  8388608    3.29    3.28     20.3957     20.4569    2048   
> > 622.43     624.3 1  8388608    3.29    0.04     20.3923   1637.0411   
> > 6143   1866.67  149851.2
>
> What type is the other host (hamilton2) and what is the round trip delay?
> Is it on the same local network?

Yes of course, hamilton2 is on our local network. And of course, this is 
completely independet of hamilton2, it can be reproduced with any local 
system (as long as this system has full network speed, of course ;) ).


Round trip delay, e.g. the ping time?

Hmm, interesting!


2.4.27:
=====
bernd@wigner bernd>ping hamilton2
PING hamilton2.pci.uni-heidelberg.de (129.206.21.202): 56 data bytes
64 bytes from 129.206.21.202: icmp_seq=0 ttl=64 time=0.1 ms
64 bytes from 129.206.21.202: icmp_seq=1 ttl=64 time=0.1 ms
64 bytes from 129.206.21.202: icmp_seq=2 ttl=64 time=0.1 ms
64 bytes from 129.206.21.202: icmp_seq=3 ttl=64 time=0.1 ms
64 bytes from 129.206.21.202: icmp_seq=4 ttl=64 time=0.1 ms
64 bytes from 129.206.21.202: icmp_seq=5 ttl=64 time=0.1 ms


2.6.11.3
======
bernd@wigner bernd>ping hamilton2
PING hamilton2.pci.uni-heidelberg.de (129.206.21.202): 56 data bytes
64 bytes from 129.206.21.202: icmp_seq=0 ttl=64 time=0.9 ms
64 bytes from 129.206.21.202: icmp_seq=1 ttl=64 time=0.4 ms
64 bytes from 129.206.21.202: icmp_seq=2 ttl=64 time=0.5 ms
64 bytes from 129.206.21.202: icmp_seq=3 ttl=64 time=0.4 ms
64 bytes from 129.206.21.202: icmp_seq=4 ttl=64 time=0.4 ms
64 bytes from 129.206.21.202: icmp_seq=5 ttl=64 time=0.4 ms



Thanks,
 Bernd

-- 
Bernd Schubert
Physikalisch Chemisches Institut / Theoretische Chemie
Universität Heidelberg
INF 229
69120 Heidelberg
e-mail: bernd.schubert@xxxxxxxxxxxxxxxxxxxxx


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