You should first try to run gfn-xtb alone and see if that parallelizes
for a system like yours, specially the size.
I doubt that gfn-xtb would really parallelize over many cores, unless
you have a pretty large QM system.
Adrian
On 3/10/21 11:12 PM, wangjianing_mail wrote:
> [External Email]
>
> Dear Amber user:
>
>
> I successfully used the gfn-xTB in amber QM/MM, by modifying sander/qm2_extern_orc_module.F90, but low parallel efficiency problem appeared.
> However both 'num_threads=12' in orc namelist of amber input file 、'%pal NPROCS 12 end' in orc_job.tpl and 'export OMP/MVK_NUM_THREADS' can not be efficiently parallel.
>
>
> Both scheme can only increase the speed by up to about 10% than 1 core scheme, and even reduce the computational efficiency, I think this is abnormal. Can someone give me any help here?
>
>
> #SI
> software: Amber18(gnu openmpi) openmpi 3.1.4 orca 4.2.1 gcc 4.8.5 openMP 201107
> test reslut
>
> method orc-num_threadsxtb-pal NPORCS OPENMP ps/d
> xtb 1 1 164
> xtb 1 1 1267
> xtb 12 1 163
> xtb 1 12 121.8
> b3lyp 1 1 /0.17
> b3lyp 20 1 /0.17
> b3lyp 1 20 / 1.83
> Regards,
> Jia-Ning Wang
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--
Dr. Adrian E. Roitberg
V.T. and Louise Jackson Professor in Chemistry
Department of Chemistry
University of Florida
roitberg.ufl.edu
352-392-6972
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Received on Thu Mar 11 2021 - 06:30:02 PST
