Intel Compiler – Inaccurate G! step errors

Thanks for the info. Honestly I don’t have an exact idea of what ‘not as expected means’. I’ll have to ask the user concerned to tak part on this forum. Their original query to our HPC support team below.

The concern is that the Innacurate G! issue only occurs on the Intel compiled version – and not on a gcc compiled version. Possible there could be slight numerical differences from using Intel MKL or similar?

I’ll try to get more detail / ask the user to post here directly.

Many Thanks!

I get some strange error during the run:



core.optimization.LineMinimizer: (0) Inaccurate G! step= 3.8147e-08 Deriv= -239.863 Finite Diff= 4.62715e+07



Otherwise the run finishes normally, but the scores of the optimization process are not accurate in the end. The collaborator does not manage to replicate this on his cluster with the same scripts that I am using. Could it be that something did not compile right? Do you perhaps have a log file that they could look at?



The collaborators are using the QB3 cluster (at UCSF) and they don’t use the MPI version. They have:

From the user…

“Output is not as expected” means that the total_score at the end of relax run are not the same. Perhaps the difference is not significant. When I run it with gcc compiled version, relax gives a final total_score below -200. While running relax with intel compiled version gave me total_scores between -190 and -167. I could do several runs to generate statistics on the scores if that would help. 

The score files look like this: 

==> gcc_TestRun_Relax.sc <==

SEQUENCE:

SCORE: total_score dslf_fa13    fa_atr    fa_dun   fa_elec fa_intra_rep       fa_rep       fa_sol hbond_bb_sc hbond_lr_bb    hbond_sc hbond_sr_bb       omega     p_aa_pp pro_close      rama       ref description

SCORE:    -205.193     0.000  -413.155   104.034   -55.167        0.940       40.477      236.847     -17.384     -35.506     -11.994     -20.385       6.055     -25.877     0.234   -10.497    -3.814 relax_1BE9_clean_0001

==> intel_TestRun_Relax.sc <==

SEQUENCE:

SCORE: total_score dslf_fa13    fa_atr    fa_dun   fa_elec fa_intra_rep       fa_rep       fa_sol hbond_bb_sc hbond_lr_bb    hbond_sc hbond_sr_bb       omega     p_aa_pp pro_close      rama       ref description

SCORE:    -167.911     0.000  -413.977    79.443   -47.998        0.960       77.783      237.462     -11.119     -32.917      -8.990     -19.018       6.097     -22.813     0.512    -9.521    -3.814 relax_1BE9_clean_0001

Many thanks for the input. Have collected averages on 100 models for both our compiled intel/mvapich2 version and the gcc version in the download from this site.

The intel compiled version gives lower, and more variable ‘total_score’ values.  Would appreciate any info to pass to user r.e. whether this is as expected / within reason?

Many Thanks,