[ExI] homebrew cold freon bath super computer

[Tomasz Rola]

On Fri, 9 Mar 2012, spike wrote:

> We have a tool at work which is a cold Freon bath: it uses the kind of 
> Freon we can still have, no chlorine, and maintains the Freon down to 
> minus 20 celcius.  I heard from a colleague they were getting rid of it.  
> I have half a mind to try to buy it at auction if I can get it for a 
> song.  Reasoning: we could set up a heat sink for a homebrew 
> supercomputer.
> 
> Freon is a low conductor, so we should be able to submerge a circuit 
> card in that stuff, ja?  A couple years ago a cell phone won a big chess 
> tournament which included two grandmasters (it beat one of them and drew 
> the other, not by phoning a friend but by doing all the calcs right 
> there in realtime.)  So modern phones make plenty of MIPS (processor 
> hipsters, help me here please.) I also know that phones are considered 
> electronic waste once they get about three yrs old, tossed into the 
> trash.
> 
> Idea: we get some application which is calculation intensive but does 
> not require a huge amount of communication between nodes such as chess 
> or Mersenne prime search, collect a bunch of these discarded phones, 
> take the processor cards out of them, remove the batteries and replace 
> with an external power source, figure out some kind of I/O system such 
> as bluetooth, stack the cards, submerge the whole mess in cold freon and 
> BOOM, we have a great poor-man's highly parallel super computer, ja?
> 
> Would that be a cool science fair project or what?

Or what, I think. I mean, if you'd like some results out of this, better 
aim for as much practicality as possible.

Used phones might be fine computing devices as long as you can have your 
software installed on them. Imagine making custom Android images for five 
different phone models. Without technical specs. And producers highly 
unwilling to cooperate. Some of Android phones had been rooted, some not. 
So this could be as easy as downloading root image or making one by 
yourself. You could also make the soft using Android SDK and install it as 
usual but I'm not sure this would give the best performance.

With some modifications, your plan could be doable:

1. Don't buy this freon bath, you won't need it. Instead, put X amount of 
cash into envelope.

2. Dig the phones out of trash, clean them up, install software updates 
and as many free apps as you can find, sell on eBay, put Y amount of 
cash into same envelope.

3. Take envelope, take (X+Y) bucks out, buy yourself used 100Mbps switch 
on eBay (5-8 ports should suffice for a start, but if you can spot 
cheap 16 ports, grab it). 1Gbps switch would be nicer (more future proof) 
but they eat more cash.

4a. For the rest of the cash buy yourself some cheap Linux based micros 
with ARM cpu and 200-something megs of ram, like BeagleBone or Raspberry 
Pi

4b. You may consider buying and dismantling old broken laptops - their 
cpus may have better floating point performance, should be cheaper than 
BeagleBones, plus you can sell unused parts - basically, anything from 
last 6-8 years should fit

5. Install your soft (Beowulf, maybe?), connect the plugs, run run run.

6. Don't worry about temperature, if you don't overclock you should be 
fine with air cooling (and maybe custom made big box with few grand 
voltage regulated 120+mm propellers and many holes) - but I would measure 
temps all the time, just in case.

At least this is how I would do this.

No matter if you go 4a or 4b route, the extra and most important bonus is, 
you don't need to reverse engineer the bloody phone to run what you need. 
One way or another you get a platform that is Linux friendly and runs 
your apps natively, whithout asking anybody for permission or 
circumventing whimsical EULAs.

Sorry if after modifications the plan is not exotic enough for you. Seems 
to me, exotic is what makes you tick :-).

6b. If you really want to use freon and will be unhappy without it, 
consider old fridge as supercomputer case. This will probably make your 
head explode when you start dealing with ice on circuits, but if only 
freon makes your day...

6c. You will have to keep disks out of the freezer all the time. This may 
contribute to their faster demise or you will make a custom box to keep 
them stable. I mean hard disks. Solids should be ok as long as you stay 
inside their working specs.

Regards,
Tomasz Rola

--
** A C programmer asked whether computer had Buddha's nature.      **
** As the answer, master did "rm -rif" on the programmer's home    **
** directory. And then the C programmer became enlightened...      **
**                                                                 **
** Tomasz Rola          mailto:tomasz_rola at bigfoot.com             **