LPLANE: Difference between revisions
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For {{TAG|LPLANE}}=.TRUE., the data distribution in real space is done plane wise. | |||
Any combination of {{TAG|NPAR}} and {{TAG|LPLANE}} can be used. | |||
Generally, {{TAG|LPLANE}}=.TRUE. reduces the communication band width during the FFT's, but at the same time it unfortunately worsens the load balancing on massively parallel machines. | |||
{{TAG|LPLANE}}=.TRUE. should only be used if {{TAG|NGZ}} is at least 3×(number of nodes)/{{TAG|NPAR}}, and optimal load balancing is achieved if {{TAG|NGZ}}=''n''×{{TAG|NPAR}}, where ''n'' is an arbitrary integer. | |||
If {{TAG|LPLANE}}=.TRUE. and if the real space projector functions ({{TAG|LREAL}}=.TRUE. or ON or AUTO) are used, it might be necessary to check the lines following | |||
real space projector functions | |||
total allocation : | |||
max/ min on nodes : | |||
The max/ min values should not differ too much, otherwise the load balancing might worsen as well. | |||
== Related Tags and Sections == | == Related Tags and Sections == | ||
{{TAG|NPAR}}, | {{TAG|NPAR}}, | ||
Revision as of 10:16, 4 April 2014
LPLANE = [logical]
Default: LPLANE = .TRUE.
Description: LPLANE switches on the plane-wise data distribution in real space.
For LPLANE=.TRUE., the data distribution in real space is done plane wise. Any combination of NPAR and LPLANE can be used.
Generally, LPLANE=.TRUE. reduces the communication band width during the FFT's, but at the same time it unfortunately worsens the load balancing on massively parallel machines. LPLANE=.TRUE. should only be used if NGZ is at least 3×(number of nodes)/NPAR, and optimal load balancing is achieved if NGZ=n×NPAR, where n is an arbitrary integer.
If LPLANE=.TRUE. and if the real space projector functions (LREAL=.TRUE. or ON or AUTO) are used, it might be necessary to check the lines following
real space projector functions total allocation : max/ min on nodes :
The max/ min values should not differ too much, otherwise the load balancing might worsen as well.
Related Tags and Sections
NPAR, NCORE, LSCALU, NSIM, KPAR