Installation with Intel or PGI compilers

[Satish Balay]

On Mon, 7 Apr 2008, amjad ali wrote:

> *Hello all,
> 
> I installed PETSc with intel compilers. Please comment on that what is the
> difference between the PETSc installed with gnu compilers and the PETSC
> installed with intel compilers. Any difference in efficiency? or what so
> ever?
> 
> What you say if we intall PETSc with PGI compilers and also we use
> MPI-profiler/debugger (available in PGI Cluster Toolkit) for PETSc
> applications? Is it possible? and beneficial?

We expect Intel compilers to be able to optimize code better than GNU
compilers. Perhaps PGI might do the same.

Its best to run your code [with PETSc compiled with the desired
compilers - and optimization options] and run with -log_summary to
compare performance differences.

And we have no experience with PGI Cluster Toolkit or its usefulness.

Note: The choice of compilers [and their cost/benifit] varies
depending on the usage.

- For code development - debuggability matters. gnu compilers work
reasonably well for this usage [with gdb, valgrind, etc..]

- For production runs, a 10% performance difference might not matter
for code that runs for less than an hour. But it might be significant
for long-running jobs.

etc..

Satish