Hi all,
In my calculation i didnt set the NPAR tag and got this warning;
For optimal performance we recommend that you set |
| NPAR = approx SQRT( number of cores) |
| This will greatly improve the performance of VASP for DFT. |
| The default NPAR=number of cores might be grossly inefficient |
| on modern multi-core architectures or massively parallel machines. |
| Unfortunately you need to use the default for hybrid, GW and RPA |
| calculations.
Does it affects the result of the calculation or just increase the required time for calculation?
thank you
NPAR setting
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ccccc
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Infant
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Re: NPAR setting
I'm not sure but the result should not be altered by the NPAR setting. Isn't it?
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Vahid Askarpour
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Re: NPAR setting
I usually use NPAR=sqrt(# of cpus) for DFT. For hybrid calculations, I use the default, i.e., NPAR=# of cpus. I have noticed that NPAR does affect the number of bands. So if you set NBANDS=26 in the INCAR and you use NPAR=30 (for say HSE with 30 cpus), then in the OUTCAR, you will find NBANDS=30 and not 24. Somehow, VASP increases NBANDS to make it divisible by NPAR.
Vahid
Vahid