[Beowulf] Haswell as supercomputer microprocessors

[John Hearns]

On Mon, 3 Aug 2015 12:06:27 PM Mikhail Kuzminsky wrote:

> Current Intel Haswell E5 v3 may also have 18 = 2**4 +2 cores.  Is
> there some sense to try POWER BQC or SPARC64 XIfx ideas (not exactly),
> and use only 16 Haswell cores for parallel computations ? If the
> answer is "yes", then how to use this way under Linux ?

Doing this with Linux predates BGQ for instance - the whole cpuset idea came from SGI and was used on their Itanic Altix systems to provide a boot CPU set that would have all system processes confined into and then the rest of the cores were available for jobs.

When we used to use Torque I agitated for cpuset support, and for it to be done in a way that would allow this.

We use Slurm now, but I've never looked at how easy to make it work in the boot cpuset type mode - it's probably just a matter of telling it there are
N-1 cores per node and ensuring that it doesn't try and claim the same core you're using as the boot cpuset. :-)


Plus one to Chris with cpusets.
Cpusets not only on Itanium - I used them on a large memory UV system.
I Can see more and more people speccing high memory x86 systems these days, and they certainly should be looking at using cpusets.


I have often though we should have 'donkey engine' CPUs for HPC.
I thought these were the small enginers which powered up very large shipboard engines.
I may have that wrong!  https://en.wikipedia.org/wiki/Steam_donkey

As Mikhail says, you run the OS and the batch system daemons on there, leaving the rest of the CPUs for 100% flat out HPC work.


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