Subject: PC clusters for CompChem - next survey

From: Grzegorz Bakalarski <[email-masked]>
Date: Sat, 10 May 2003 16:24:55 +0200

Dear All,

According to my search in CCL archives there was no discussion about clusters for computational
chemistry since at least half a year, so I'd hope we can start next turnaround.
I'd not like to start next war or any flames so I'd like to ask for concrete living examples
or firm guidelines.
At the moment there is also new opportunity because Itenium 2 (64-bit) processors become more popular
and even more - the next generation AMD 64-bit Opteron procesors have just been become available.
Still we can also consider very fast 32-bit Pentium IV or Xeon  from Intel or Athlons from AMD
(with speed from 2 to over 3GHz).
Having this in mind please share your opinions on current trends in building PC clusters for
use in computational chemistry. To be more specific one can think about most popular programs
like gamess, gaussian, amber, NWchem, Tripos , MSI programs - note: this should be rather
general purpose computational cluster and not only for running QM or only MD ...
It's obvious that price/performance is main criterium but still functionality, reliability,
stability is of importance.
Particular aspect are the following
* size of nodes: 1 or 2 or 4 or more processors per node (up to now it seems that 2 processor
  nodes had best price/performance but what about new 4 processor Opteron motherboard)
* performance: Opteron vs Itenium 2 vs Xeon (or maybe PIV or Athlons should be considered)
* functionality: aren't Opterons (or even Itanium 2) too new - problems with software ?
* stability: Athlons were known because of overheating - what about Opterons??? Still
  new motherboards are not well tested
* the size of memory (I know that more is better, but what is enough): 2GB, 4GB, 8GB
* interconnect: is 1Gb enough or should we consider other solutions (which ones?) ...
  the size of cluster maybe from 32 up to 128 nodes (depending on funds and prices)

Any other comments or issues are welcome!

Thanks for essential responses.

Kind regards,

P.S. I guess more are interested in, so please post to the list if possible. 
     I'll summarize answers of course ....