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Subject: Re: [OMPI users] Gigabit ethernet (PCI Express) and openmpi v1.2.4
From: Allan Menezes (amenezes007_at_[hidden])
Date: 2007-12-18 17:49:54

Hi Allan,

This suggest that your chipset is not able to handle the full PCI-E
speed on more than 3 ports. This usually depends on the way the PCI-E
links are wired trough the ports and the capacity of the chipset
itself. As an exemple we were never able to reach fullspeed
performance with Myrinet 10g on IBM e325 nodes, because of chipset
limitations. We had to make the node changed to solve the issue.
Running several instances of NPtcp should somewhat show the bandwith
limit of the PCI-E bus on your machine.

Hi Aurelien or anybody else,
     How do you run several instances of NPtcp simultaneouly between two idential nodes a1, a2 through 3 similat gigabit etherenet cards with different subnets and switches.
a1: eth0 - eth2 - eth3 -
a2: eth0 - eth2 - eth3 -
This is the way i do it currently.
on a1:>./NPtcp
ssh a2
a2> ./NPtcp -h -n 50
for tcp b/w of eth0 and so on sor eth2 and eth3
I do not how to do it simultaneosly ie check the total b/w of eth0+eth2+eth3 at the same time in one invocation of ./NPtcp.
I can do it with mpirun and NPmpi
Can some one please tell me how to do it with NPtcp because i do not know.
Allan Menezes