The ABINIT Users Mailing List ( CLOSED )

[mperez@mpi-halle.mpg.de]

Hi

 i was wandering whether there is any point in optimising the code in
order to get fast runs

 let me explain my point, i have MPI-installed 5.2.3 on an opteron cluster
for -O3 and -O0, using ifort compiler (and gcc)
When i  go through the "internal tests", (section 3. How to make the
internal tests and the speed tests ? (sequential version only)) everything
is ok, but when i go through the "other tests" (4. How to make the other
tests ?)
the number of FAILURES that i get is larger for -O0 (11 cases) than for
-O3 (6 cases)

Then, if i use -O2 with some extra optimisation, and, including "safety
options", i get 6 failed cases, whilst using "implicit -O2 with no safety
options", i get only 3 failed cases (THE BEST I'VE SEEN)

i imagine that the best way to make sure my implementation is not too bad
is to use "exactly" the same compilation flags for "ifort" that have been
used by the abinit team in the build up of binaries (for opteron)

Some final point: there are two tests in the section "parall", which FAIL
for any level of optimisation that i use (always): tests G and I

Please let me know whether i should consider seriously some optimisation,
and how i should do that

thanks

Manolo


PS:
(a)"safety options":
-fltconsistency -IPF_fltacc -pc80 -mp1 -fp-model strict -prec-div -prec-sqrt
(b)"extra optimisation": -xW -tpp7
(c)"implicit -O2 without safety options": only library linking options =>
-i-static -Bstatic -static -lmpichf90 -lmpich -lpthread -lrt