[Beowulf] Advice on 4 CPU node configurations

[madskaddie at gmail.com]

  Hi all

  We are designing a new HPC system for our lab. We are shifting ideas
around (our budget is of 30K euro).

  We do CFD and mainly run two types of stuff:

  - Finite volume, with neighbour (hallo cell) comunication (so,
communication with neighbours only)

  - Direct Numerical Simulations, with pseudo-spectral methods, imposing
ALL_TO_ALL communication

  Because there are users of a proprietary finite volume code we are in
need of at least one machine with a good RAM figure (48GB or above).

  So, we would like to tap into the beowulfers pound of knowledge and get
your opinions/comments/experience on...

  - 4 CPU configurations in the same mobo, like this one:

   http://www.supermicro.com/Aplus/system/2U/2042/AS-2042G-TRF.cfm

  here, one of our questions has to do with bandwith bottlenecks (with this
solution we are thinking we could use DDR or QDR Infiniband to join
different nodes)

  - Some comments on AMD 12 or 8 core Opteron 6100+ CPUs

  - Registred vs unbuf memmory

  - Intel alternatives?

  anything else we should think/look at ?


Thanks,


Gil Brandão

-- 
"
It can't continue forever. The nature of exponentials is that you push
them out and eventually disaster happens.
"
Gordon Moore  (Intel co-founder and author of the Moore's law)