[General] Any linux gurus?

Fri Dec 13 11:13:07 CST 2013

Method of Moment, Computational ElectroMagnertics.

Program is called Vlox

On Fri, Dec 13, 2013 at 10:47 AM, David <ainut at knology.net> wrote:

>  MoM CEM vlox -- could you expand those acronyms, please?  Is this a
> logistics planning tool?
>
>
>
> Stephan Henning wrote:
>
> -David
>
>  Hmm, sounds interesting. The problem is distributed a little currently,
> you can think of it kind of what is being done as a form of monte carlo, so
> the same run will get repeated many times with light parameter adjustments.
> Each of these can be distributed out to the compute nodes very easily,
> currently this is being done with condor.
>
>
>  -James
>
>  It's a MoM CEM tool called vlox.
>
>
>
> On Fri, Dec 13, 2013 at 5:43 AM, James Fluhler <j.fluhler at gmail.com>wrote:
>
>>  I'm just curious what simulation program are you running? I've used a
>> number in the past that also utilize the GPU's for processing.
>>
>> James F.
>>
>> On Dec 12, 2013, at 11:28 PM, David <ainut at knology.net> wrote:
>>
>>   IIRC, the good thing about this cluster is the automagic load
>> leveling.  Your existing binary may not run at max optimization but if the
>> task can be spread among processors, Beowulf does a nice job of it.  If
>> each computer has it's own GPU(s), then all the better.
>>
>> You can test it right there without changing anything on the system's
>> disks.  Just create and run all the cluster members off a CD.
>>
>> Then to test, pick the fastest one of them (maybe even your existing Xeon
>> box), run your benchmark, record execution time, then boot all the other
>> machines in the cluster and run it again.  There are only about two dozen
>> steps to set it up.  One professor even put most of those, along with
>> automatic cluster setup(!) as a downloadable you can boot off of.  That
>> leaves half a dozen steps to tweak the cluster together, then you're good
>> to go.  I have one of those CD's around here somewhere and I can get
>> details if you're interested.  Something to play with.  I did it with only
>> 4 pc's around the house with some code and even though the code was never
>> designed for a cluster (just multiprocessing), I got about 40% decrease in
>> execution time.  The code was almost completely linear execution so I'm
>> surprised it got any improvement but it did.
>>
>> David
>>
>>
>> Stephan Henning wrote:
>>
>> -WD
>>
>>  I believe it's either ext3 or ext4, I'd have to ssh in and check when I
>> get back on Monday.
>>
>>  -David
>>
>>  I'll check into the Beowulf and see what that would entail. I'll try
>> and talk with the developer and see what their thoughts are on the
>> feasibility of running it on a cluster. They may have already gone down
>> this path and rejected it, but I'll check anyway.
>>
>>
>> On Thu, Dec 12, 2013 at 6:16 PM, David <ainut at knology.net> wrote:
>>
>>> Sounds like a perfect candidate for a Beowulf cluster to me.  There are
>>> possibly some gotcha's but you'll have the same problems with just a single
>>> computer.
>>>
>>> Velly intewesting.
>>>
>>> Stephan Henning wrote:
>>>
>>>>  -WD
>>>>
>>>> The GPUs are sent data in chunks that they then process and return. The
>>>> time it takes a GPU to process a chunk can vary, so I assume the bottle
>>>> necks we were seeing was when several of the GPU cores would finish at
>>>> about the same time and request a new chunk and the chunk they needed
>>>> wasn't already in RAM, so the drive array would take a heavy hit.
>>>>
>>>> Beyond that, I can't really give you a numerical value as to the amount
>>>> of data they are dumping into the pcie bus.
>>>>
>>>>
>>>> -David
>>>>
>>>> Ya, not sure an FPGA exists large enough for this, it would be
>>>> interesting though.
>>>>
>>>> While the process isn't entirely sequential, data previously processed
>>>> is reused in the processing of other data, so that has kept us away from
>>>> trying a cluster approach.
>>>>
>>>> Depending on the problem, anywhere from minutes per iteration, to weeks
>>>> per iteration. The weeks long problems are sitting at about 3TB I believe.
>>>> We've only run benchmark problems on the SSDs up till now, so we haven't
>>>> had the experience of seeing how they react once they start really getting
>>>> full.
>>>>
>>>>  Sadly, 2TB of RAM would not be enough. I looked into this Dell box (
>>>> http://www8.hp.com/us/en/products/proliant-servers/product-detail.html?oid=4231377#!tab=features<
>>>> http://www8.hp.com/us/en/products/proliant-servers/product-detail.html?oid=4231377#%21tab=features>)
>>>> that would take 4TB, but the costs were insane and it can't support enough
>>>> GPUs to actually do anything with the RAM...
>>>>
>>>>
>>>>
>>>>  <<<snip>>>
>>>
>>>
>>> _______________________________________________
>>> General mailing list
>>> General at lists.makerslocal.org
>>> http://lists.makerslocal.org/mailman/listinfo/general
>>>
>>
>>
>>
>> _______________________________________________
>> General mailing listGeneral at lists.makerslocal.orghttp://lists.makerslocal.org/mailman/listinfo/general
>>
>>
>>   _______________________________________________
>> General mailing list
>> General at lists.makerslocal.org
>> http://lists.makerslocal.org/mailman/listinfo/general
>>
>>
>> _______________________________________________
>> General mailing list
>> General at lists.makerslocal.org
>> http://lists.makerslocal.org/mailman/listinfo/general
>>
>
>
>
> _______________________________________________
> General mailing listGeneral at lists.makerslocal.orghttp://lists.makerslocal.org/mailman/listinfo/general
>
>
>
> _______________________________________________
> General mailing list
> General at lists.makerslocal.org
> http://lists.makerslocal.org/mailman/listinfo/general
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.makerslocal.org/pipermail/general/attachments/20131213/6827057d/attachment.html>