Running results are different for an application from compiling -O0 option and -O3 option

[Lyndon_L_]

Hi,

    I am running some climate models and met an annoying problem. If the climate model was compiled wih debug mode -O0 (using intel/12.1.9.293 and openmpi 1.4.3), then the running result is totally different from that running model compiled with -O3 option.

    Could someone please tell me if this is normal?  Should a model compiled with debug mode be used in production runs?

     Many thanks.

Cheers,

Lyndon.

[Patrick_F_Intel1]

Hello Lyndon,

There are intel compiler folks at the C++ forum: Intel® C++ Compiler forum - Intel® Developer Zone

There is a fortran compiler forum at Intel® Fortran Compiler for Linux* and Mac OS X* | Intel® Developer . and Intel Visual Fortran Compiler for Windows forum - Intel® Developer .. 

If you submit your post there, you'll get (IMO) better advice since it looks like a compiler question.

Pat

[Lyndon_L_]

I re-sbumit my posts there. Thanks Pat...

-Lyndon