[Beowulf] liquid cooling for HPC

[Einar Rustad]

On 5. des. 2012, at 10:50, Jörg Saßmannshausen <j.sassmannshausen at ucl.ac.uk> wrote:

> Dear all,
> 
> I am sure the subject has been covered a number of times, however, I have been 
> to the Machine Evaluation Workshop last week here in Liverpool and this 
> company here
> http://www.iceotope.com/
> done something which I found rather unusual. Rather then using pipes to cool 
> the CPUs or dipping the whole node into silicon oil (messy) or water, they are 
> using a hydrofluoro carbon compound to move the heat from the motherboard to a 
> chilling plate. There are pros and cons of course. As the whole motherboard is 
> sealed into the box you cannot change it yourself. It needs to be send back to 
> them. On the flip side, it appears the the excess heat could be used a bit more 
> efficiently.

Seymour Cray pioneered the fluorocarbon cooling in the Cray-2, I believe he used 
some 144 gallons of the stuff for the whole machine which was housed in a tank with
transparent windows "so you could see more Cray":-). The liquid was pumped around
and cooled in a heat exchanger. 
This molecules in this type of liquid can be designed with different boiling temperatures. 
As far as I can recall one version (not the one used by Cray) can boil at 27 degrees C at 
normal atmospheric pressure and such be used in a heat pipe without having to actively
pump it around.

> I was wondering whether somebody has some experiences with 'water' cooling in 
> HPC and would like to share it with me? I am thinking of getting something 
> like that or similar (no decision has been made right now) for the next server 
> I am getting. However, as that is new technology to me (the 'water' cooling), 
> before I venture into that I would like to hear some first hand experiences, 
> not necessarily with the company/product mentioned above which is only an 
> example here.
> 
> All the best from a wet London
> 
> Jörg
> 
> -- 
> *************************************************************
> Jörg Saßmannshausen
> University College London
> Department of Chemistry
> Gordon Street
> London
> WC1H 0AJ 
> 
> email: j.sassmannshausen at ucl.ac.uk
> web: http://sassy.formativ.net
> 
> Please avoid sending me Word or PowerPoint attachments.
> See http://www.gnu.org/philosophy/no-word-attachments.html
> 
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Einar Rustad, VP Business Development
er at numascale.com			
Mob: +47 9248 4510