Dell 1600SC + 82540EM poor performance..HELP NEEDED

Stephane.Martin at Stephane.Martin at
Thu Jul 24 11:12:54 EDT 2003

Jeff Layton a écrit :
> Stephane,
>    What kind of switch (100 or 1000)? Have you looked
> at the switch ports? Are they connecting at full or half
> duplex? How about the NICs? You'll see bad performance
> with a duplex mismatch between the NICs and switch.
> Are you forcing the NICs or are they auto-negiotiating?
> Good Luck!
> Jeff
> > Hello,
> >
> > We have recently received 48 Bi-xeon Dell 1600SC and we are performing
> > some benchmarks to tests the cluster.
> > Unfortunately we have very bad perfomance with the internal gigabit
> > card (82540EM chipset). We have passed linux netperf test and we have
> > only 33 Mo
> >
> > between 2 machines. We have changed the drivers for the last ones,
> > installed procfgd and so on... Finally we had Win2000 installed and
> > the last driver
> >
> > from intel installed : the results are identical... To go further we
> > have installed a PCI-X 82540EM card and re-run the tests : in that way the
> >
> > results are much better : 66 Mo full duplex...
> > So the question is : is there a well known problem with this DELL
> > 1600SC concernig the 82540EM integration on the motherboard ????
> >
> > As anyone already have (heard about) this problem ?
> > Is there any solution ?
> >
> > thx for your help
> >
> --
> Dr. Jeff Layton
> Chart Monkey - Aerodynamics and CFD
> Lockheed-Martin Aeronautical Company - Marietta


For our tests we are connected to a 4108GL (J4865A), we have done all necessary checks (maybe we've have forget something very very big ????) to
ensure the validity of our mesures. The ports have been tested with auto neg on, then off and also forced. We have also the same mesures when
connected to a J4898A. The negociation between the NIcs ans the two switches is working.

When using a tyan motherboard with the 82540EM built-in and using the same benchs and switches ans the same procedures (drivers updates and
compilations from Intel, various benchs, different OS) the results are correct (80 to 90Mo). 

All our tests tends to show that dell missed something in the integration of the 82540EM in the 1600SC series...if not we'll really really appreciate
to know what we are missing there cause here we have a 150 000 dollars cluster said to be connected with a network gigabit having network perfs of
three 100 card bonded (in full duplex it's even worse !!!!!). If the problem is not rapidly solved the 48 machines will be returned....

thx a lot for your concern,


Stephane Martin         Stephane.Martin at 
Tel: 04 76 61 20 31   
Informatique et distribution Web:
ENSIMAG - Antenne de Montbonnot 
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