[SCore-users-jp] Re: [SCore-users] gigabit/trunking

[Shinji Sumimoto]

Hi, Nick.
  
From: Nick Birkett <nrcb ＠ streamline-computing.com>
Subject: [SCore-users] gigabit/trunking
Date: Thu, 16 May 2002 07:18:41 +0100
Message-ID: <200205160618.g4G6If312664 ＠ pecan.comlab.ox.ac.uk>

nrcb> Hi - we have been installing SCore primarily with Myrinet 2000.
nrcb> 
nrcb> We would like to hear of any experiences of users with the following
nrcb> equipment:
nrcb> 
nrcb> (1) Trunked ethernet using eepro100 fast ethernet cards ?
nrcb> (2) Gigagbit ?
nrcb> (3) Has anyone tried network trunking using gigabit (expenive for switches I know!!)
nrcb> i.e 2 gigabit cards per host as an alternative to Myrinet2000 ?

If you use Network Trunking on Gigabit Ethernet, you should use
Ethernet Switches and NICs which support JUMBO FRAME on 66MHz 64bit
PCI in order to achieve high bandwidth because of lackness of PCI DMA
bandwidth. On PCI-X or on multiple PCI buses, the performance may be
increased, but I have not tested..

See: 
http://www.pccluster.org/score/dist/score/html/en/overview/pm-perf.html

We have tested Syskonect 9843 NICs, 3Com 996B-T and Broadcom 5701 NICs
using Network Trunking with JUMBO FRAMEs.

We have also tested Intel PRO100T, PRO1000XT but not tested with JUMBO
FRAMEs.

nrcb> As regards gigabit, the cheapest equipment is the eepro1000 copper base card.
nrcb> The kernel driver in the 2.4.18 SCORE-5.0.0 kernel is Intel  4.0.7 I think, so maybe ok with this.
nrcb> I know early versions of e1000 had lockup problems using copper card. Maybe 
nrcb> the latest Intel version is better ( >= 4.1.7). I think Shinji Sumimoto did not
nrcb> recommend copper cards in the past, but maybe it is better with newer driver.
nrcb> 
nrcb> Has anyone got an automatic tool for tuning the maxsend and backoff values for pm/ethernet and trunked network,
nrcb> I couldn't find one in the Score 5 documentation ?

Sorry We do not have, but I think I wont to make it. The problem is
that the optimal value is depend on number of nodes and NIC hardare
and applications.. I think some application programs or communication
benchmarks are required for tuning..

Shinji.

nrcb> 
nrcb> Thanks,
nrcb> 
nrcb> Nick
nrcb> 
nrcb> _______________________________________________
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nrcb> 
nrcb> 
------
Shinji Sumimoto, Fujitsu Labs
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