LSCALU: Difference between revisions
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{{TAGDEF|LSCALU|[logical]|.FALSE.}} | {{TAGDEF|LSCALU|[logical]|.FALSE.}} | ||
Description: {{TAG|LSCALU}}. | Description: {{TAG|LSCALU}} switches on the parallel LU decomposition (using scaLAPACK) in the orthonormalization of the wave functions. | ||
---- | ---- | ||
For {{TAG|LSCALU}}=.TRUE. the LU decomposition in the orthormalization of the wave functions is done in parallel, using scaLAPACK routines. | |||
Provided, of course, {{TAG|LSCALAPACK}}=.TRUE. and VASP was compiled with scaLAPACK support ([[Precompiler_flags|precompiler flag]]: -DscaLAPACK). | |||
In many cases, the scaLAPACK LU decomposition based is ''slower'' than the serial LU decomposition (compare the timing <tt>ORTHCH</tt> in the respective {{FILE|OUTCAR}} files). Hence the default is {{TAG|LSCALU}}=.FALSE. | |||
(subspace rotations, however, are still done using scaLAPACK). | |||
== Related Tags and Sections == | == Related Tags and Sections == | ||
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{{TAG|LSCAAWARE}} | {{TAG|LSCAAWARE}} | ||
{{sc|LSCALU|Examples|Examples that use this tag}} | |||
---- | ---- | ||
[[Category:INCAR]][[Category:parallelization]] | [[Category:INCAR]][[Category:Performance]][[Category:parallelization]] | ||
Revision as of 17:47, 11 March 2019
LSCALU = [logical]
Default: LSCALU = .FALSE.
Description: LSCALU switches on the parallel LU decomposition (using scaLAPACK) in the orthonormalization of the wave functions.
For LSCALU=.TRUE. the LU decomposition in the orthormalization of the wave functions is done in parallel, using scaLAPACK routines. Provided, of course, LSCALAPACK=.TRUE. and VASP was compiled with scaLAPACK support (precompiler flag: -DscaLAPACK).
In many cases, the scaLAPACK LU decomposition based is slower than the serial LU decomposition (compare the timing ORTHCH in the respective OUTCAR files). Hence the default is LSCALU=.FALSE. (subspace rotations, however, are still done using scaLAPACK).
Related Tags and Sections
NPAR, NCORE, LPLANE, NSIM, KPAR, LSCALAPACK, LSCAAWARE