bench.options.dat
and
bench.options.log
. Here,
options
is an abbreviation of the options
describing the benchmark run (essentially, it is a concatenation of
the relevant command-line parameters). (Alternatively, you can
enforce the DOS 8.3 filename restrictions by using the
"-dos
" command-line switch.)
bench.options.dat
is a comma-delimited text
file containing the results in tabular form, suitable for import into
a spreadsheet. (We use commas rather than tabs because tabs have an
annoying tendency to get converted into spaces, especially by email
programs.) The first column is the transform size, and subsequent
columns are the speed or accuracy results for each transform. (Speed
is measured in "mflops" and
accuracy is the mean fractional error. See the methodology section for an explanation of
these quantities.)
At the top of each column is the name of the FFT corresponding to the data in the column. These names are, in most cases, the last name of the author of the code. A complete listing of the FFTs in the benchmark, along with links to where they may be downloaded, can be found in the FFT Software section of this manual.
When transform speed is being measured, the last line of
bench.options.dat
contains "normalized average"
speeds for all the FFTs. This is a kind of summary of the results, and
is separated by a blank line from the rest of the data. (We caution
users, however, that average results are probably not as useful as the
results for a particular problem size of interest.) The average is
computed as follows:
bench.options.log
contains verbose descriptions of
the benchmark computations. (It is mainly intended for us, the
developers, as a debugging tool and as an aid in understanding the
results that other people might send us.)
-h
-submit
-name s
s
the root name for the output files (the
default is "bench"). The output files are then
s.options.dat
and
s.options.log
. We usually like to choose a
name that describes the machine we are running on (e.g. "trs80",
"eniac", or "ppc686").
-dos
-1d
-3d
You must specify either -1d
or -3d
; otherwise, no benchmark will be performed. You may specify both.
-s
-a
-p2
-np2
-pa
-size N
N
(for 3D
transforms, NxNxN
). (In this case, output will
only be to stdout
.) The default is to benchmark a
hard-coded range of representative sizes. If this option is used, the
-p2
, etcetera, options are ignored.
-maxmem MB
MB
megabytes of memory, at
most (actually, a bit more memory than this will be used). The
default is 50 megabytes. This determines the maximum transform size
that is benchmarked by the program. (We usually set it to 10-20%
below the actual amount of memory available.)