Memory requirement for GW step2

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chandra_sarap1
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Memory requirement for GW step2

#1 Post by chandra_sarap1 » Mon Jul 26, 2021 4:41 pm

Dear all,

How do I know the memory requirement for a GW calculations.

I am using 10 nodes (each 192 GB) and 128 cores for step 2 calculation of GW. And it prints following lines in OUTCAR.

total amount of memory used by VASP MPI-rank0 3896020. kBytes
=======================================================================

base : 30000. kBytes
nonlr-proj: 35877. kBytes
fftplans : 7242. kBytes
grid : 81346. kBytes
one-center: 6594. kBytes
wavefun : 3734961. kBytes



This looks like I need memory around 4 GB per core to run the calculation and 1920 GB/128 core will give 15 GB per core.
But, the calculation terminated with error due to insufficient memory. I am wondering what will be the issues.

Can anyone please help me if my math is correct or what should be the ideal number of nodes can I use.


Thanks,
Chandra

ferenc_karsai
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Re: Memory requirement for GW step2

#2 Post by ferenc_karsai » Thu Jul 29, 2021 7:51 am

Which version of VASP are you using?
Can you please post your calculation (POSCAR, POTCAR, INCAR, KPOINTS, OUTCAR).

marie-therese.huebsch
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Re: Memory requirement for GW step2

#3 Post by marie-therese.huebsch » Mon Aug 09, 2021 11:47 pm

Dear Chandra,

Thank you for asking about memory requirements.

First of all, let me caution that the memory requirements written to the OUTCAR file are estimates. It is not possible to get the actual memory requirements easily in general.

But specific to your calculation, I wonder if you could check the minimum memory per core available on your compute engine. From the information you provided, it is not completely clear to me how you end up with a total of 128 cores distributed across 10 nodes. How many cores per node does your architecture have?

Best regards,
Marie-Therese

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