Re: CCL:Re: fortran Compiler for Linux Box. Options?

 "William T. Rankin" writes:
 >> I am willing to go freeware, but I would spend the money on
 >> a good Fortran compiler to gain the performance. (I also believe
 >> there is no freeware fortran compiler for f90 code!)
 >I picked up some information form The Portland Group, who markets
 >auto-parallelizing FORTRAN compilers for Linux.  You may want to
 >look them up at
 >Now having said that, I will point out that even with the best
 >tools, simply running a compiler over existing serial FORTRAN
 >codes will most likely not produce highly scalable parallel code
 >without some sort of programmer direction from within the source.
 I've used both g77 the Portland Group compiler for AMBER 5.0 both with and
 without MPI (message passing interface).  I've had excellent results using
 Portland Group's compiler.  I didn't try the auto-parallelization, but I
 did compile MPI with PG's C compiler and AMBER 5.0 with PG's f77 compiler.
 Here are the results I got (times are in seconds) on my dual PPro 200MHz:
 g77 opt -O6, ewald test:
 g77 MPI opt -O6, dual proc, ewald test:
 pgcc full opt, ewald test:
 pgcc MPI full opt, dual proc, ewald test:
 So, dual processors with g77 is faster than one with PGF77, but
 PGF77 with dual processors is definitely the best.   Paralogic
 is going to let me test on their 4 processor platforms-
 if this code scales well on intels, it'd definitely be a much
 cheaper way to get the performance we need.
 Email: dek (- at -)   David Konerding   WWW: