EMC offers dual socket 28 physical core processors. That's a lot of
computer.
On Tue, Aug 24, 2021, 1:33 PM Lux, Jim (US 7140) via Beowulf <
beowulf@beowulf.org> wrote:
> Yes, indeed.. I didn't call out Limulus, because it was mentioned earlier
> in the thread.
>
> And another reason why you might want your own.
> Every so often, the notice from JPL's HPC goes out to the users -
> "Halo/Gattaca/clustername will not be available because it is reserved for
> Mars {Year}" While Mars landings at JPL are a *big deal*, not everyone is
> working on them (in fact, by that time, most of the Martians are now
> working on something else), and you want to get your work done. I suspect
> other institutional clusters have similar "the 800 pound (363 kg) gorilla
> has requested" scenarios.
>
>
> On 8/24/21, 11:34 AM, "Douglas Eadline" <deadl...@eadline.org> wrote:
>
>
> Jim,
>
> You are describing a lot of the design pathway for Limulus
> clusters. The local (non-data center) power, heat, noise are all
> minimized while performance is maximized.
>
> A well decked out system is often less than $10K and
> are on par with a fat multi-core workstations.
> (and there are reasons a clustered approach performs better)
>
> Another use case is where there is no available research data center
> hardware because there is no specialized sysadmins/space/budget.
> (Many smaller colleges and universities fall into this
> group). Plus, often times, dropping something into a data center
> means an additional cost to the researchers budget.
>
> --
> Doug
>
>
> > I've been looking at "small scale" clusters for a long time (2000?)
> and
> > talked a lot with the folks from Orion, as well as on this list.
> > They fit in a "hard to market to" niche.
> >
> > My own workflow tends to have use cases that are a big "off-nominal"
> - one
> > is the rapid iteration of a computational model while experimenting
> - That
> > is, I have a python code that generates input to Numerical
> > Electromagnetics Code (NEC), I run the model over a range of
> parameters,
> > then look at the output to see if I'm getting what what I want. If
> not, I
> > change the code (which essentially changes the antenna design),
> rerun the
> > models, and see if it worked. I'd love an iteration time of "a
> minute or
> > two" for the computation, maybe a minute or two to plot the outputs
> > (fiddling with the plot ranges, etc.). For reference, for a radio
> > astronomy array on the far side of the Moon, I was running 144
> cases, each
> > at 380 frequencies: to run 1 case takes 30 seconds, so farming it
> out to
> > 12 processors gave me a 6 minute run time, which is in the right
> range.
> > Another model of interaction of antnenas on a spacecraft runs about
> 15
> > seconds/case; and a third is about 120 seconds/case.
> >
> > To get "interactive development", then, I want the "cycle time" to
> be 10
> > minutes - 30 minutes of thinking about how to change the design and
> > altering the code to generate the new design, make a couple test
> runs to
> > find the equivalent of "syntax errors", and then turn it loose - get
> a cup
> > of coffee, answer a few emails, come back and see the results. I
> could
> > iterate maybe a half dozen shots a day, which is pretty productive.
> > (Compared to straight up sequential - 144 runs at 30 seconds is more
> than
> > an hour - and that triggers a different working cadence that
> devolves to
> > sort of one shot a day) - The "10 minute" turnaround is also
> compatible
> > with my job, which, unfortunately, has things other than computing -
> > meetings, budgets, schedules. At 10 minute runs, I can carve out a
> few
> > hours and get into that "flow state" on the technical problem, before
> > being disrupted by "a person from Porlock."
> >
> > So this is, I think, a classic example of "I want local control" -
> sure,
> > you might have access to a 1000 or more node cluster, but you're
> going to
> > have to figure out how to use its batch management system (SLURM and
> PBS
> > are two I've used) - and that's a bit different than "self managed
> 100%
> > access". Or, AWS kinds of solutions for EP problems. There's
> something
> > very satisfying about getting an idea and not having to "ok, now I
> have to
> > log in to the remote cluster with TFA, set up the tunnel, move my
> data,
> > get the job spun up, get the data back" - especially for iterative
> > development. I did do that using JPLs and TACCs clusters, and
> "moving
> > data" proved to be a barrier - the other thing was the "iterative
> code
> > development" in between runs - Most institutional clusters discourage
> > interactive development on the cluster (even if you're only sucking
> up one
> > core). If the tools were a bit more "transparent" and there were
> "shared
> > disk" capabilities, this might be more attractive, and while
> everyone is
> > exceedingly helpful, there are still barriers to making it "run it
> on my
> > desktop"
> >
> > Another use case that I wind up designing for is the "HPC in places
> > without good communications and limited infrastructure" - The
> notional
> > use case might be an archaeological expedition wanting to use HPC to
> > process ground penetrating radar data or something like that. (or,
> given
> > that I work at JPL, you have a need for HPC on the surface of Mars)
> - So
> > sending your data to a remote cluster isn't really an option. And
> here,
> > the "speedup" you need might well be a factor of 10-20 over a single
> > computer, something doable in a "portable" configuration (check it as
> > luggage, for instance). Just as for my antenna modeling problems,
> turning
> > an "overnight" computation into a "10-20 minute" computation would
> change
> > the workflow dramatically.
> >
> >
> > Another market is "learn how to cluster" - for which the RPi
> clusters work
> > (or "packs" of Beagleboards) - they're fun, and in a classroom
> > environment, I think they are an excellent cost effective solution to
> > learning all the facets of "bringing up a cluster from scratch", but
> I'm
> > not convinced they provide a good "MIPS/Watt" or "MIPS/liter" metric
> - in
> > terms of convenience. That is, rather than a cluster of 10 RPis, you
> > might be better off just buying a faster desktop machine.
> >
> > Let's talk design desirements/constraints
> >
> > I've had a chance to use some "clusters in a box" over the last
> decades,
> > and I'd suggest that while power is one constraint, another is noise.
> > Just the other day, I was in a lab and someone commented that "those
> > computers are amazingly fast, but you really need to put them in
> another
> > room". Yes, all those 1U and 2U rack mounted boxes with tiny fans
> > screaming is just not "office compatible" And that kind of brings
> up
> > another interesting constraint for "deskside" computing - heat.
> Sure you
> > can plug in 1500W of computers (or even 3000W if you have two
> circuits),
> > but can you live in your office with a 1500W space heater?
> > Interestingly, for *my* workflow, that's probably ok - *my*
> computation
> > has a 10-30% duty cycle - think for 30 minutes, compute for 5-10.
> But
> > still, your office mate will appreciate if you keep the sound level
> down
> > to 50dBA.
> >
> > GPUs - some codes can use them, some can't. They tend, though, to be
> > noisy (all that air flow for cooling). I don't know that GPU
> manufacturers
> > spend a lot of time on this. Sure, I've seen charts and specs that
> claim
> > <50 dBA. But I think they're gaming the measurement, counting on the
> user
> > to be a gamer wearing headphones or with a big sound system. I will
> say,
> > for instance, that the PS/4 positively roars when spun up unless
> you’ve
> > got external forced ventilation to keep the inlet air temp low.
> >
> > Looking at GSA guidelines for office space - if it's "deskside" it's
> got
> > to fit in the 50-80 square foot cubicle or your shared part of a 120
> > square foot office.
> >
> > Then one needs to figure out the "refresh cycle time" for buying
> hardware
> > - This has been a topic on this list forever - you have 2 years of
> > computation to do: do you buy N nodes today at speed X, or do you
> wait a
> > year, buy N/2 nodes at speed 4X, and finish your computation at the
> same
> > time.
> >
> > Fancy desktop PCs with monitors, etc. come in at under $5k, including
> > burdens and installation, but not including monthly service charges
> (in an
> > institutional environment). If you look at "purchase limits"
> there's some
> > thresholds (usually around $10k, then increasing in factors of 10 or
> 100
> > steps) for approvals. So a $100k deskside box is going to be a tough
> > sell.
> >
> >
> >
> > On 8/24/21, 6:07 AM, "Beowulf on behalf of Douglas Eadline"
> > <beowulf-boun...@beowulf.org on behalf of deadl...@eadline.org>
> wrote:
> >
> > Jonathan
> >
> > It is a real cluster, available in 4 and 8 node versions.
> > The design if for non-data center use. That is, local
> > office, lab, home where power, cooling, and noise
> > are important. More info here:
> >
> >
> https://urldefense.us/v3/__https://www.limulus-computing.com__;!!PvBDto6Hs4WbVuu7!f3kkkCuq3GKO288fxeGGHi3i-bsSY5P83PKu_svOVUISu7dkNygQtSvIpxHkE0XDpKU4fOA$
> >
> https://urldefense.us/v3/__https://www.limulus-computing.com/Limulus-Manual__;!!PvBDto6Hs4WbVuu7!f3kkkCuq3GKO288fxeGGHi3i-bsSY5P83PKu_svOVUISu7dkNygQtSvIpxHkE0XD7eWwVuM$
> >
> > --
> > Doug
> >
> >
> >
> > > Hi Doug,
> > >
> > > Not to derail the discussion, but a quick question you say desk
> > side
> > > cluster is it a single machine that will run a vm cluster?
> > >
> > > Regards,
> > > Jonathan
> > >
> > > -----Original Message-----
> > > From: Beowulf <beowulf-boun...@beowulf.org> On Behalf Of
> Douglas
> > Eadline
> > > Sent: 23 August 2021 23:12
> > > To: John Hearns <hear...@gmail.com>
> > > Cc: Beowulf Mailing List <beowulf@beowulf.org>
> > > Subject: Re: [Beowulf] List archives
> > >
> > > John,
> > >
> > > I think that was on twitter.
> > >
> > > In any case, I'm working with these processors right now.
> > >
> > > On the new Ryzens, the power usage is actually quite tunable.
> > > There are three settings.
> > >
> > > 1) Package Power Tracking: The PPT threshold is the allowed
> socket
> > power
> > > consumption permitted across the voltage rails supplying the
> > socket.
> > >
> > > 2) Thermal Design Current: The maximum current (TDC) (amps)
> that can
> > be
> > > delivered by a specific motherboard's voltage regulator
> > configuration in
> > > thermally-constrained scenarios.
> > >
> > > 3) Electrical Design Current: The maximum current (EDC) (amps)
> that
> > can be
> > > delivered by a specific motherboard's voltage regulator
> > configuration in a
> > > peak ("spike") condition for a short period of time.
> > >
> > > My goal is to tweak the 105W TDP R7-5800X so it draws power
> like
> > the
> > > 65W-TDP R5-5600X
> > >
> > > This is desk-side cluster low power stuff.
> > > I am using extension cable-plug for Limulus blades that have an
> > in-line
> > > current meter (normally used for solar panels).
> > > Now I can load them up and watch exactly how much current is
> being
> > pulled
> > > across the 12V rails.
> > >
> > > If you need more info, let me know
> > >
> > > --
> > > Doug
> > >
> > >> The Beowulf list archives seem to end in July 2021.
> > >> I was looking for Doug Eadline's post on limiting AMD power
> and
> > the
> > >> results on performance.
> > >>
> > >> John H
> > >> _______________________________________________
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> > >
> > >
> > > --
> > > Doug
> > >
> > > _______________________________________________
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> > >
> >
> >
> > --
> > Doug
> >
> > _______________________________________________
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> >
>
>
> --
> Doug
>
>
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