Andreas Boklund andreas at amy.udd.htu.se
Wed Oct 18 01:58:46 PDT 2000

I replied to Daniel but i might as well translate my reply to him to
english and add a few things and send it to the list.

I have build 2 clusters with the purpose of running fluent on them.

The first one was

 20 * Pentium III 500 	128SDRAM
 1 * Cisco Catalyst 1900

 The second one is the one that im "fine tuning" right now.
 1 * dual Pentium III 866 256RDRAM
 9 * dual Pentium III 800 256RDRAM
 1 * Cisco Catalyst 2900

Our calculations has a LOT of chemistry in them so i dont think its fair
to draw any standard conclusions from them. 
But maybe a few pointers:

They dont require much bandwith.
Although each iteration i do with my new cluster sends approx 150-200MB of
information /iteration. One iteration takes just over a minute to
complete. This might sound like a lot but the switch is not an issue.

On very few computers it has pretty good scalability but somewhere around
10-12 processors the gain of adding another one is very small. (we need
the time so we added a few more anyway).

This chart http://www.exjobb.udd.htu.se/2000/sv3/25/Image3.gif (is in
swedish) but it showes the time it takes for FOXHOLE with different number
of nodes to complete our problem, and it shows the time it takes for a
Dell with 4*550 and 1GBSDRAM. 

Fluent is pretty RAM hungry although for the nodes i "might" have been
able to use 128MB but im considering to go to 512 on the master.


And if anyone know Swedish (i know that Daniel does) you can read our
Bachelor thesis on:
Unfortunately we had to cut away a lot of the technical stuff :(

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