Hi
I am running some tests on an HPC cluster, altering the size of reads to test
the performance of the file system.
I am using python, and for sequential reads not using netCDF4 the read rate is
pretty constant across different read sizes. However, when I introduce the
netCDF4 library the smaller and larger reads see a dip in performance with a
peak on the medium sized reads (creating a hill-like profile). The peak in the
netCDF4 performance is at about the same read rate as the non-netCDF4 reads.
The peak is at reads of about 1MB.
We think this could be to do with buffering somewhere in the NetCDF library.
Does anyone know of such buffering that we should be aware of?
Many thanks
Matt
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Matthew Jones
PhD Student
Atmosphere, Oceans and Climate
Department of Meteorology,
University of Reading
Room 288, ESSC, Harry Pitt Building,
3 Earley Gate, Reading, RG6 6AL, UK
Ext: 5214
https://www.linkedin.com/pub/matthew-jones/8b/b81/25a
http://www.met.reading.ac.uk/users/users/1887
