[Beowulf] why we need cheap, open learning clusters

[Lux, Jim (337C)]

On 5/12/13 3:42 PM, "Charlie Peck" <charliep at cs.earlham.edu> wrote:

>On May 12, 2013, at 3:11 PM, "Lux, Jim (337C)" <james.p.lux at jpl.nasa.gov>
>wrote:
>
>> ...
>> Of some interest would be whether the LittleFE folks think that using
>>rPis
>> instead Via Mobos would be worthwhile.  By the time you stick a SD card
>>in
>> the Pi and arrange power supplies, I'm not sure the price difference is
>> all that much. 
>
>I sent a couple of students off with rPi boards recently to see if we
>could do just that.  Unfortunately their report wasn't good, they had
>reliability problems and having only the HDMI video made working with
>them difficult.  

Yes, that's what's stopped me fooling with rPI.  I suppose there's some
sort of HDMI>VGA converter or some other workaround, but that takes it out
of the "stuff I can do with things I find in my garage" bucket. I'm not
about to go out and spend $30 on a converter box to use a $30 computer.
And all my HDMI or DVI compatible monitors are already in use.


>We're thinking about looking at PC104 formfactor boards again to see if
>we can find something in that range that would work.  Our goal is to
>produce something that's truly carry-on (we have a MicroFe design now
>that's 2 Mini-ITX boards in a Pelican briefcase that BCCD developers use
>but we'd like more cores).
>
>> And LittleFE is truly commodity.. The architecture doesn't care which
>> Mini-ITX mobo you get.. If you want to stack up Intel D2550s instead of
>> the Via boards, it's no real matter.
>
>The latest model of LittleFe does use Atom D2550's, and we're looking at
>AMD based APU units for the future.  One of our design goals is to
>provide a platform that people could easily build any Mini-ITX based
>system on, we sell the frame kit separately for just this reason.

Aha..

You should be able to fit quite a few Mini-ITX boards into a "carry on"
compatible Pelican case. I just did a bunch of stuff with a Pelican 1510
(the largest that is guaranteed carry on) and a Mini-ITX based embedded PC
is inside (in a M350 enclosure from Mini-box). I think you could fit at
least 6 Mini ITXes in there. They're 6.7x6.7" and the I/O shield is 1"
high. The 1510 is 19.75x11x7.6". I think you could stack 8 high in the 11
inch dimension.  Cooling would be a challenge.. You might want to go with
one of the aluminum cases, or cut holes for fans, or space them out a bit.
Actually, power supply might be the biggest challenge.   They probably
draw 50-60W running full out, so 8 of them is 400W. That's a potentially
bulky power supply.

>
>charlie