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>To: <address@hidden> >From: "Christelle Riou" <address@hidden> >Subject: Performance problem with NetCDF-3.5 >Organization: Capgemini Group >Keywords: 200501110902.j0B92tv2004020 netCDF performance Hi Christelle, > I encounter performance problem in using the NetCDF-3.5 library. > > When i add a large variable in a file, it takes not very long, but > the next "get" instruction is very long even if I force the > data_mode before the "get" instruction. The "get" instruction seems > to move variables and that takes very long time. > > What can I do to avoid this ? The "get" functions in netCDF don't move any bytes in the file. They might take a long time if you are getting values that are not close to each other on disk. For example, if you have written a large 2D variable by rows and are accessing values by column, it is possible that each value could require a separate disk access, which would be slow. Do you have a small example that would allow us to duplicate the problem here, so we could suggest a solution? --Russ _____________________________________________________________________ Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu/staff/russ