Scyld ClusterWare HPC: Reference Guide
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linpack

Name

linpack -- Run the linpack benchmark

Synopsis

linpack [-h ] [-n N]

Description

The linpack shell script will create a configuration file for the xhpl program and run it.

This script is a portable, non-optimized version of the High Performance Linpack (HPL) benchmark. It is intended for verification purposes only. The numbers it reports should not be interpreted as benchmark results and should not be used for performance characterization.

linpack will use the private Ethernet interconnect by default.

Options

The following options are available to the linpack program.

-h,--help

Print the command usage message and exit.

-n N

Use the specified problem size rather than the default size of 3000.

-c,--config-only

Generate the xhpl configuration file but do not run xhpl. This file may be used as a starting point for tuning the benchmark parameters.

-v,--verbose

Show progress messages.

-V,--version

Show the command version and exit.

Examples

This is example we are using 16 processors is a 4x4 grid and achieving just over 6 Gflops of performance. 

[user@cluster user] $ linpack
============================================================================
HPLinpack 1.0  --  High-Performance Linpack benchmark  --  September 27, 2000
Written by A. Petitet and R. Clint Whaley,  Innovative Computing Labs.,  UTK
============================================================================
An explanation of the input/output parameters follows:
T/V    : Wall time / encoded variant.
N      : The order of the coefficient matrix A.
NB     : The partitioning blocking factor.
P      : The number of process rows.
Q      : The number of process columns.
Time   : Time in seconds to solve the linear system.
Gflops : Rate of execution for solving the linear system.

The following parameter values will be used:

N      :    3000 
NB     :      60 
P      :       4 
Q      :       4 
PFACT  :   Right 
NBMIN  :       4 
NDIV   :       2 
RFACT  :   Right 
BCAST  :  1ringM 
DEPTH  :       1 
SWAP   : Mix (threshold = 64)
L1     : transposed form
U      : transposed form
EQUIL  : yes
ALIGN  : 8 double precision words

----------------------------------------------------------------------------

- The matrix A is randomly generated for each test.
- The following scaled residual checks will be computed:
   1) ||Ax-b||_oo / ( eps * ||A||_1  * N        )
   2) ||Ax-b||_oo / ( eps * ||A||_1  * ||x||_1  )
   3) ||Ax-b||_oo / ( eps * ||A||_oo * ||x||_oo )
- The relative machine precision (eps) is taken to be          1.110223e-16
- Computational tests pass if scaled residuals are less than           16.0

============================================================================
T/V                N    NB     P     Q               Time             Gflops
----------------------------------------------------------------------------
W11R2R4         3000    60     4     4               2.89          6.232e+00
----------------------------------------------------------------------------
||Ax-b||_oo / ( eps * ||A||_1  * N        ) =        0.0174384 ...... PASSED
||Ax-b||_oo / ( eps * ||A||_1  * ||x||_1  ) =        0.0184414 ...... PASSED
||Ax-b||_oo / ( eps * ||A||_oo * ||x||_oo ) =        0.0037694 ...... PASSED
============================================================================

Finished      1 tests with the following results:
              1 tests completed and passed residual checks,
              0 tests completed and failed residual checks,
              0 tests skipped because of illegal input values.
----------------------------------------------------------------------------

End of Tests.
============================================================================

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