open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello everybody,

I've been running Telemac in my personal computer for some time without any issue. So, I decided to install Telemac in a cluster to share it with other people in my research group. But I have found its performance is unexpectedly worse now.

My first test was using Telemac 2D in parallel in both computers using 2 cores and without MUMPS. In my personal computer it took 1:45 hours to end. In the cluster it lasted 3:46 hours.

I thought it might be related to a wrong parallel configuration in the cluster. So, I tried in serial mode. The results were very similar. In my personal computer Telemac took 0:45 hours to end, while in the server it took 1:45 hours.

I don't find any sense. Does anyone know what might be going on here?

My personal computer details are:

Intel Core i5-2300 2.80GHz - 8 GB RAM
Windows 7 Professional 64 bits
Intel Visual Fortran 64 Compiler XE Version 12.0.0.104

The cluster nodes details are:

Intel Xeon E5620 4C 2.40Ghz 12M - 16Gb DDR3 1333Mhz
CentOS release 5.6 64 bits
GNU Fortran (GCC) 4.7.2 20121015 64 bits

Hello

Just a few indications:

• The CPU on your cluster is from the 'Westmere' generation, so 1 generation older than the one on your desktop 'Sandy Bridge'. The typical performance difference between the two generations is 10 to 20%.
• The CPU clock on your desktop is also 17% higher
• The Intel compiler tends to give faster results

So this goes some way explaining the difference, but there must be something else to give such a large difference in performance (especially when Linux is typically more efficient than Windows for running TELEMAC).

Let's see if someone can help you check your configuration on each machine.

Hello again,

Thank you so much for your quick reply. Your indications are in agreement with what I expected. I've ported other models from the same desktop to the same cluster, and performance always decreased a little (10%-20%).

But the decrease here is so big that I think I could be doing something wrong. I could test or change whatever you think it is causing the issue.