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Timing the Level 2 and 3 BLAS

Timing of the Level 2 and 3 BLAS routines may be requested from one of the linear equation input files, or by using a special BLAS format provided for compatibility with previous releases of LAPACK. The BLAS input format is the same as the linear equation input format, except that values of NX are not read in. The BLAS input format is requested by specifying `BLAS' on the first line of the file.

Three input files are provided for timing the BLAS with the matrix shapes encountered in the LAPACK routines. In each of these files, one of the parameters M, N, and K for the Level 3 BLAS is on the order of the blocksize while the other two are on the order of the matrix size. The first of these input files also times the Level 2 BLAS, and we include the single precision real version of this data file here for reference:

BLAS timing, REAL data, K small
5                          Number of values of M
10 20 40 60 80             Values of M
5                          Number of values of N
10 20 40 60 80             Values of N
2                          Number of values of K
2 16                       Values of K
1                          Number of values of INCX 
1                          Values of INCX
1                          Number of values of LDA
81                         Values of LDA
0.05                       Minimum time in seconds
none                       Do not time the sample BLAS
SB2
SB3

Since the Fortran BLAS do not contain any sub-blocking, the block size NB is not required and its value is replaced by that of INCX, the increment between successive elements of a vector in the Level 2 BLAS. Note that we have specified ``none'' on line 13 to suppress timing of the sample BLAS, which are redundant in this case.


next up previous contents
Next: Timing the Nonsymmetric Eigenproblem Up: More About Timing Previous: The Linear Equation Timing   Contents
Susan Blackford 2001-08-13