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Subject: Re: [OMPI users] Gigabit ethernet (PCI Express) and openmpi v1.2.4
From: Gleb Natapov (glebn_at_[hidden])
Date: 2007-12-17 07:14:42


On Sun, Dec 16, 2007 at 06:49:30PM -0500, Allan Menezes wrote:
> Hi,
> How many PCI-Express Gigabit ethernet cards does OpenMPI version 1.2.4
> support with a corresponding linear increase in bandwith measured with
> netpipe NPmpi and openmpi mpirun?
> With two PCI express cards I get a B/W of 1.75Gbps for 892Mbps each ans
> for three pci express cards ( one built into the motherboard) i get
> 1.95Gbps. They all are around 890Mbs indiviually measured with netpipe
> and NPtcp and NPmpi and openmpi. For two it seems there is a linear
> increase in b/w but not for three pci express gigabit eth cards.
> I have tune the cards using netpipe and $HOME/.openmpi/mca-params.conf
> file for latency and percentage b/w .
> Please advise.
What is in your $HOME/.openmpi/mca-params.conf? May be are hitting your
chipset limit here. What is your HW configuration? Can you try to run
NPtcp on each interface simultaneously and see what BW do you get.

--
			Gleb.