Robin,
>I have a coleague working in the area of CAD, who is interested in
>what kind of difference it would make if a CAD run took 2 hours, or 15
>minutes, instead of the current 8-12 hours. He thought (and I agree)
>that there ought to be a parallel to how long it takes to compile a
>program. They are in the equivalent of the era where we submitted a
>card deck and waited a day for turn around.
In the 'old' days factors other than cpu time were a significant portion of
the elapsed time needed to get a job done.
These days there is no connection between the time taken to compile a
program and the time taken to execute it.
> Does anyone know of studies about what changes when compiles
>drastically change the amount of time they take?
Yes. The main issues are number of bytes of source code (these days
these are mostly contained within header files) and the degree of compiler
optimization that has been requested.
I am not sure whether you are asking how to increase the speed of execution
of the CAD program, or increase the rate it is compiled at. Your timing
information
suggests the former.
In the former case you have three options:
1) Compile the source at a greater optimization level (assumes you have
source).
2) Change hardware platforms. CAD programs are floating-point intensive.
I see you work for Sun, who make good web servers, but their
floating-point
performance is not exactly stunning. You colleague might like to
check out SGI
or HP.
3) Parallel processing. Much talked about, but rarely achieved in
practice.
If it is the latter case I would suggest looking at the include
files. Over time source files
accumulate includes that they no longer need. CAD, so the source could be
Fortran,
off hand I cannot think of any include checking tools for Fortran on Sun.
derek
--
Derek M Jones tel: +44 (0)
1252 520 667
Knowledge Software
Ltd mailto:[EMAIL PROTECTED]
Applications Standards Conformance Testing http://www.knosof.co.uk
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