next up previous contents
Next: Global dimensioning parameters Up: Installation of Previous: User configuration

   
Performance and special considerations

The script siteconfig_lapw is provided for general configuration and compilation of the WIEN97 package. When you call this script for the first time and follow the suggested answers, WIEN97 should run on your system.(see 11.2.2)

The codes in the individual subdirectories /SRC_program are compiled using make. The file Makefile is generated during installation using Makefile.orig as template.

In some directories source files *.frc and param.inc_r/c files, which contain both, the real and complex (for systems without inversion symmetry) version of the code are present. You create these versions with make and make complex respectively. (The *.frc files will than be preprocessed automatically).

For timing purposes a subroutine CPUTIM is used in lapw0/1/2 and specific routines for IBM-AIX, HP-UX, DEC-OSF1, Fujitsu-S100, SGI-IRIX NEC and Cray are available. On other systems cputim_generic.c should work,

On some HP systems you may encounter problems like: ``stack growth failure''. You may recompile with -K, reconfigure your Unix-kernel (with increased stack-size) or put large arrays in the respective program into COMMONS.

Most of the CPU time will be spent in lapw1 and (to a smaller extent) in lapw2 and lapw0. Therefore we recommend to optimize the performance for these 3 programs:

Find out which compiler options (man f77) make these programs run faster. You could specify a higher optmization (-O3), specify a particular processor architecture (-qarch=pp2 or -R10000, ....) or a preprocessor (like kapp or vast).

In addition some fortran routines are provided in different versions which may run faster on your hardware or you can optimize various parameters:


next up previous contents
Next: Global dimensioning parameters Up: Installation of Previous: User configuration

2000-04-11