Scaling of processor vs. number of atoms
Clicked A Few Times
2:11:07 PM PST - Sun, Nov 21st 2010
Dear all;

We are trying to run DFT optimization (with B3LYP/6-31g**) for a large system having couple of hundred atoms. Our system contains H, C and S atoms. We have a total of 16 GB shared RAM. In order to perform efficient calculation, I need to know the requirement of the number of processors versus number of atoms. Could you please suggest the scaling requirement of number of processor with the number of atoms for B3LYP/6-31g**?

Thank you
ram

Forum Regular
6:36:24 PM PST - Sun, Nov 21st 2010
Hi Ram,

How many processors do you have on your system ? Do all the processors share the same 16GB RAM ?

Best,
-Niri

Clicked A Few Times
8:08:08 PM PST - Sun, Nov 21st 2010
Dear Niri;

We have couple of hundreds of processors (cores) and 16 GB of RAM is shared among the 6 cores on our system.

Thank you very much in advance for your suggestion.

ram

Forum Vet
4:01:18 PM PST - Tue, Jan 11th 2011
You should be able to use 64 or 128 processors. Make sure to set the memory per core in your input deck as "memory 2000 mb", so you have some room for the OS.


Bert


Quote:Ram Nov 22nd 3:08 am
Dear Niri;

We have couple of hundreds of processors (cores) and 16 GB of RAM is shared among the 6 cores on our system.

Thank you very much in advance for your suggestion.

ram


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