I must change the FFLAGS_OPT := -O1 to build and run CESM

[xlong@ncsu_edu]

Linux cluster
Intel ifort and icc 10.1.022
mpich2 1.3a2
CESM 1_0_5

If I leave FFLAGS_OPT := -O2, the model fails at build stage.(build the land component)

I change it to FFLAGS_OPT := -O1, then cesm can build and run successfully.

My question is ,
How much the FFLAGS_OPT := -O1 will slow down the model?
Will it affect the scientific result? (I guess no?)

Thanks

 

[alisonfangdada@icloud_com]

Hey, I came into the same problem (cesm1_0_4, intel). I'm wandering which file and which place did you change about the FFLAGS_OPT?