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NCAR / VAPOR

VAPOR is the Visualization and Analysis Platform for Ocean, Atmosphere, and Solar Researchers
https://www.vapor.ucar.edu/
BSD 3-Clause "New" or "Revised" License
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raw2vdc doesn't scale past 8 threads on casper #2954

Open clyne opened 2 years ago

clyne commented 2 years ago

The raw2vdc command doesn't seem to be able to use more than 8 threads effectively on casper.

To reproduce:

  1. Start an interactive session on casper with the following command (replacing the account key as needed)

execcasper -A NVST001 -l select=1:ncpus=16:mem=20GB

  1. Create a VDC file with the ASD 2022 MURaM data:

vdccreate -vars3d eosT -bs 128:128:128 -dim 2352x2016x2016 foo.vdc

  1. Convert the data with raw2vdc:

time raw2vdc -nthreads 16 -var eosT foo.vdc /glade/p/cisl/vast/vapor/data/Source/Raw/MURaM/ASD2022_Rempel_2352x2016x2016/eosT.000000

  1. Run 'top' and observe the CPU utilization. It never goes above 800%. Moreover, running the above command with 8 threads instead of 16 yields roughly the same execution time.
sgpearse commented 2 years ago

Marking as medium for now - revisit if there is a more pressing need.

sgpearse commented 2 years ago

Note: may affect other converters