[swanmodel-users] Inconcictencies when compiling with ifort

[Rafael G. <r.g...@me...>]

Hi guys,

has anyone had issues before with inconsistent results in swan code
compiled with ifort please? I had that recently and have still not figured
out why.

My inconsistencies arise when running an ifort-compiled binary on machines
with intel and AMD architectures. there are differences that randomly
appear over the domain and oscillate in magnitude over time. For example,
the plot attached shows differences in Hs over a 7.5-day nonstationary
simulation ran on intel and AMD. The differences are not negligible (over
8cm in hs in some timesteps). and appear to fluctuate

On the other hand binaries compiled with gfortran produced consistent
(exactly same) results. I also played a bit with ifort optimisation flags
(O0, O2, and some other combinations) but no luck - the random differences
change but the overall magnitude is somewhat similar to the figure attached.

Has anybody experienced something similar please? Is there any specific
optimisation option flag or anything you would suggest disabling to ensure
ifort-compiled binary produces same (or at least more similar) results
regardless where it is running? I'm using version 40.91 by the way.

Thanks,
Rafael