[CP2K-user] [CP2K:15171] Re: Does CP2K allow a multi-GPU run?

[Alfio Lazzaro]

Hi,
Your command to run CP2K doesn't mention MPI (mpirun, mpiexc, ...). Are you 
running with multiple ranks?

You can check those lines in the output:

 GLOBAL| Total number of message passing processes                          
  32
 GLOBAL| Number of threads for this process                                
    4

And check your numbers.
I can guess you have 1 rank and 40 threads.
To use 4 GPUs you need 4 ranks (and less threads per rank), i.e. something 
like

export OMP_NUM_THREADS=10
mpiexec -n 4 ./cp2k.psmp -i gold.inp -o gold_pbc.out

Please check with your sysadmin on how to run with multiple MPI ranks.

Hope it helps.

Alfio



Il giorno mercoledì 21 aprile 2021 alle 09:26:53 UTC+2 ASSIDUO Network ha 
scritto:

> This is what my PBS file looks like:
>
> #!/bin/bash
> #PBS -P <PROJECT>
> #PBS -N <JOBNAME>
> #PBS -l select=1:ncpus=40:ngpus=4
> #PBS -l walltime=08:00:00
> #PBS -q gpu_4
> #PBS -m be
> #PBS -M none
>
> module purge
> module load chpc/cp2k/8.1.0/cuda10.1/openmpi-4.0.0/gcc-7.3.0
> source $SETUP
> cd $PBS_O_WORKDIR
>
> cp2k.psmp -i gold.inp -o gold_pbc.out
> ~                                                                          
>                                              ~                              
>            
>
> On Wed, Apr 21, 2021 at 9:22 AM Alfio Lazzaro <al... at gmail.com> wrote:
>
>> The way to use 4 GPUs per node is to use 4 MPI ranks. How many ranks are 
>> you using?
>>
>> Il giorno martedì 20 aprile 2021 alle 19:44:15 UTC+2 ASSIDUO Network ha 
>> scritto:
>>
>>> I'm asking, since the administrator running my country's HPC is saying 
>>> that although I'm requesting access to 4 GPUs, CP2K is only using 1. I 
>>> checked the following output:
>>>  DBCSR| ACC: Number of devices/node                                      
>>>       4
>>>
>>> And it shows that CP2K is picking up 4 GPUs.
>>>
>>> On Tuesday, April 20, 2021 at 3:00:17 PM UTC+2 ASSIDUO Network wrote:
>>>
>>>> I currently have access to 4 GPUs to run an AIMD simulation, but only 
>>>> one of the GPUs are being used. Is there a way to use the other 3, and if 
>>>> so, can you tell me how to set it up with a PBS job?
>>>
>>> -- 
>> You received this message because you are subscribed to the Google Groups 
>> "cp2k" group.
>> To unsubscribe from this group and stop receiving emails from it, send an 
>> email to cp... at googlegroups.com.
>> To view this discussion on the web visit 
>> https://groups.google.com/d/msgid/cp2k/70ba0fce-8636-4b75-940d-133ce4dbf0can%40googlegroups.com 
>> <https://groups.google.com/d/msgid/cp2k/70ba0fce-8636-4b75-940d-133ce4dbf0can%40googlegroups.com?utm_medium=email&utm_source=footer>
>> .
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20210422/36ed9901/attachment.htm>