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<TITLE>Re: [Beowulf] 1 multicore machine cluster</TITLE>
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On 4/24/09 8:07 AM, "Jonathan Aquilina" <<a href="eagles051387@gmail.com">eagles051387@gmail.com</a>> wrote:<BR>
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</SPAN></FONT><BLOCKQUOTE><FONT FACE="Calibri, Verdana, Helvetica, Arial"><SPAN STYLE='font-size:11pt'>in a way arent multicore processors taking for example 4 single core<BR>
machines and merging them into one with 1 for core processor?<BR>
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I think the term “node” is a loaded term in HPC. This is what comes to mind when I hear node, and I’m sure a lot of other people think the same: A node is a physical building block of a cluster. It has an operating system, it probably has some kind of daemon running to launch jobs submitted to a batch system. It is managed as a single unit, but may contain many processors & cores. I don’t think anyone in the HPC field would say that a cluster of 128 systems with 8 cores per system is a 1024 node cluster. They would say it is a 128 node cluster with 1024 cores. It has 128 operating system instances running, 128 pbs_moms, etc. Calling it a 1024 node cluster is misleading. Much of the management here tend to confuse node with core, but we’re a genetics research laboratory and most people don’t have a background in this.<BR>
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On 4/24/09, Glen Beane <<a href="Glen.Beane@jax.org">Glen.Beane@jax.org</a>> wrote:<BR>
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> On 4/24/09 3:03 AM, "Jonathan Aquilina" <<a href="eagles051387@gmail.com">eagles051387@gmail.com</a>> wrote:<BR>
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> im impressed with the different views everyone has. i dont know how many of<BR>
> you would agree with me a multicore processor lets say a quad is 4 nodes in<BR>
> one. could one say it like that?<BR>
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> I would not. To me a node is a physical thing. One or more processor(s),<BR>
> RAM, running its own OS instance. I have a cluster of N nodes with M cores<BR>
> per node, or N*M total cores.<BR>
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> In your example, N is 1 and M is 4.<BR>
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> One thing that annoys me is when an intern working on an MPI program keeps<BR>
> saying "node" when they really mean MPI rank since we are long past the days<BR>
> where we have a 1 to 1 mapping between MPI ranks and nodes (we don't do any<BR>
> kind of hybrid thing where we have 1 multi-threaded process per node).<BR>
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> --<BR>
> Glen L. Beane<BR>
> Software Engineer<BR>
> The Jackson Laboratory<BR>
> Phone (207) 288-6153<BR>
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--<BR>
Jonathan Aquilina<BR>
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-- <BR>
Glen L. Beane<BR>
Software Engineer<BR>
The Jackson Laboratory<BR>
Phone (207) 288-6153<BR>
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