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-   -   Slow calculation (http://www.cfd-online.com/Forums/star-ccm/88276-slow-calculation.html)

tom.j.87 May 12, 2011 11:57

Slow calculation
 
Hi, I have one question.

My computer is have: 2 cores (Pentium i3, 8gb ram). Now I count the calculation with 1 200 000 cells. One iteration takes 1 minute, but all the calculation takes 3 days. I compute with settings Run mode: Serial. CPU usage is 30%, 60% of RAM. I using as a client Windows 7 and version Star CCm 4.04 64bit. My teacher say me that I have change settings from bios: Hypertreading turn off. It seems to me that both cores are not loaded at full power. Thanks for your answer.


Regards Tom :o

MFitl May 16, 2011 02:25

Good Morning,

Quote:

Originally Posted by tom.j.87 (Post 307385)
Hi, I have one question.

My computer is have: 2 cores (Pentium i3, 8gb ram). Now I count the calculation with 1 200 000 cells. One iteration takes 1 minute, but all the calculation takes 3 days. I compute with settings Run mode: Serial. CPU usage is 30%, 60% of RAM. I using as a client Windows 7 and version Star CCm 4.04 64bit. My teacher say me that I have change settings from bios: Hypertreading turn off. It seems to me that both cores are not loaded at full power. Thanks for your answer.


Regards Tom :o

  1. You need to start the paralell mode to use more than one core. You need either a HPC license or a second starccm+ license to do so.
  2. It is recomended to use n-1 cores for performance reasons. (n = number of cores available on computer)
  3. wit more the 1e6 cells and only 8GB RAM you will run into swaping leading to very poor performance, especially on Windows.
Conclusion: Setup a 4-8Core (!Licenses for starccm+) 16-32GB Ram fast harddisk system. If you or someone in your next to you is familar with Linux I would prefere to use this at leats for the server procves, but this is only a little bit more than personal experience. And I do not want to start a Linux-is-better-than-windows-or-the-other-way-around-war, defenetly.

CU,
Matthias


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