Changes between Version 300 and Version 301 of doc/tec/changelog_2018

Timestamp:

Mar 14, 2014 7:39:24 AM (11 years ago)

Author:

raasch

Comment:

--

doc/tec/changelog_2018

@@ -29 +29 @@
 {{{#!td style="vertical-align:top"
 '''Changed:'''\\
-Adjustments for parallel NetCDF output for lccrayh/lccrayb (Cray XC30 systems). \\\\
-Environmental variables are set (.mrun.config.hlrnIII). \\
-To increase the performance of the parallel NetCDF output, the following is done:
-- The time dimensions are limited (check_parameters, data_output_2d, data_output_3d, header, netcdf, modules, read_var_list, write_var_list),
-- Update time axis by PE0 only (data_output_2d, data_output_3d),
-- Cross sections are first stored on a local array and are outputted collective (data_output_2d, netcdf),
-- Values for axis data are only written by PE0 (netcdf) and
-- No fill is set (netcdf).
+Adjustments for parallel NetCDF output on Cray XC30 systems (lccrayh/lccrayb). \\\\
+
+Changes to increase the performance of the parallel netCDF output:
+- Environmental variables, e.g. for disc striping, are set. (.mrun.config.hlrnIII)
+- The time dimensions are set to ''limited'' instead of ''unlimited''. (check_parameters, data_output_2d, data_output_3d, header, netcdf, modules, read_var_list, write_var_list)
+- Output of axis data and update of time axis is done by PE0 only. (data_output_2d, data_output_3d, netcdf)
+- Cross sections are first stored on a local array, collected by MPI_ALLREDUCE, and then output collectively. (data_output_2d, netcdf)
+- The "no fill"-attribute is set for all variables using {{{NF90_DEF_VAR_FILL}}}. This prevents netCDF from initializing the complete file (writing zero-values) at the beginning, which turned out to be extremely time consuming. (netcdf)
 '''Attention:''' So far, parallel NetCDF output is only available for 2D- and 3D-data and not for masked data. \\
-If the user choose [wiki:doc/app/d3par#netcdf_data_format netcdf_data_format] five or six, parallel output is used for 2D- and 3D-data and for masked data [wiki:doc/app/d3par#netcdf_data_format netcdf_data_format] is set internally to the value of three or four, respectively (check_parameters, time_integration).
+If the user chooses [wiki:doc/app/d3par#netcdf_data_format netcdf_data_format]{{{ = 5/6}}}, parallel output is used for 2D- and 3D-data and for masked data [wiki:doc/app/d3par#netcdf_data_format netcdf_data_format] is set internally to the value of {{{3/4}}}, respectively (check_parameters, time_integration)
 }}}
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