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Run the LAPACK Timing Programs (For LAPACK 3.0 and before)

There are two distinct timing programs for LAPACK routines in each data type, one for the linear equation routines and one for the eigensystem routines. The timing program for the linear equation routines is also used to time the BLAS. We encourage you to conduct these timing experiments in REAL and COMPLEX or in DOUBLE PRECISION and COMPLEX*16; it is not necessary to send timing results in all four data types.

Two sets of input files are provided, a small set and a large set. The small data sets are appropriate for a standard workstation or other non-vector machine. The large data sets are appropriate for supercomputers, vector computers, and high-performance workstations. We are mainly interested in results from the large data sets, and it is not necessary to run both the large and small sets. The values of N in the large data sets are about five times larger than those in the small data set, and the large data sets use additional values for parameters such as the block size NB and the leading array dimension LDA. Small data sets finished with the _small in their name , such as, and large data sets finished with _large in their name, such as Except as noted, the leading `s' in the input file name must be replaced by `d', `c', or `z' for the other data types.

We encourage you to obtain timing results with the large data sets, as this allows us to compare different machines. If this would take too much time, suggestions for paring back the large data sets are given in the instructions below. We also encourage you to experiment with these timing programs and send us any interesting results, such as results for larger problems or for a wider range of block sizes. The main programs are dimensioned for the large data sets, so the parameters in the main program may have to be reduced in order to run the small data sets on a small machine, or increased to run experiments with larger problems.

The minimum time each subroutine will be timed is set to 0.0 in the large data files and to 0.05 in the small data files, and on many machines this value should be increased. If the timing interval is not long enough, the time for the subroutine after subtracting the overhead may be very small or zero, resulting in megaflop rates that are very large or zero. (To avoid division by zero, the megaflop rate is set to zero if the time is less than or equal to zero.) The minimum time that should be used depends on the machine and the resolution of the clock.

For more information on the timing programs and how to modify the input files, please refer to LAPACK Working Note 41 [3].

If you do not wish to run each of the timings individually, you can go to LAPACK, edit the definition lapack_timing in the file Makefile to specify the data types desired, and type make lapack_timing. This will compile and run the timings for the linear equation routines and the eigensystem routines (see Sections 6.7.1 and 6.7.3).

If you encounter failures in any phase of the timing process, please feel free to contact the authors as directed in Section 6.8. Tell us the type of machine on which the tests were run, the version of the operating system, the compiler and compiler options that were used, and details of the BLAS library or libraries that you used. You should also include a copy of the output file in which the failure occurs.

Please note that the BLAS timing runs will still need to be run as instructed in 6.7.2.

next up previous contents
Next: Timing the Linear Equations Up: Further Details of the Previous: Testing the Eigensystem Routines   Contents
Julie Langou 2007-02-26