[Beowulf] Performance characterising a HPC application

[Douglas Eadline]

> On Sat, Mar 24, 2007 at 11:08:32AM -0400, Douglas Eadline wrote:
>
>> You really need two networks for GAMMA as GAMMA turns off TCP
>> while in use. Not to difficult with today's GigE-full nodes.
>> Just need extra an extra switch.
>
> I'm familiar with that requirement, yes.
>
>> > I just got a X2100 M2 machine in today. 4 GBit ports, though 2 of them
>> > nVidia.
>>
>> I was able to get 17 usecond latency (netpipe TCP ) with the nvidia
>> links on these systems. Out of the box broadcom was about
>> 40 useconds (netpipe TCP).
>
> Vanilla netpipe, stock Linux kernel?

Nothing special was done. This is a Sun Discovery
cluster. It came wired to the nvidia port. I was curious
and did some tests. Using Warewulf and RHEL4 to build
the cluster.

> That's a very good result,
> given that GAMMA with Broadcoms is only slightly better.

Yes, that what I thought as well (ran netpipe/TCP several
times to check it)

--
Doug

>
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-- 
Doug