[Ncep.list.nems.announce] Theia upgrade impact on NEMS

Gerhard Theurich theurich at sourcespring.net
Wed Nov 8 18:23:07 UTC 2017

Dear NEMS developers,

The Theia upgrade of 11/07/17 comes with an impact on NEMS applications. 
You must very likely change which ESMF module your NEMS application is 
pointing to, and rebuild your NEMS application.

The impact on NEMS comes through the ESMF module that is loaded by the 
NEMS application. Until recently, ESMF instructed the NEMS application 
to explicitly link against Intel's Small Vector Math Library SVML (via 
-lsvml). However, our current understanding is that there is an 
incompatibility of Intel's SVML and the upgraded system libraries, that 
will lead to strange numerical issues when working in optimization mode 
-O2 or above.

In order to mitigate the issue, all current ESMF installations do NOT 
instruct the application to explicitly link against SVML. We have also 
patched previous ESMF version and made them available on Theia. Old ESMF 
installations on Theia have been disabled in order to prevent 
hard-to-debug situations for when -lsvml is specified.

The consequence for NEMS applications is that you must change the ESMF 
module your application uses if currently it accesses an ESMF module 
from under (they have ALL been disabled)


or any of the following ESMF modules from under


The currently available replacement ESMF modules are:


Also, any ESMF modules starting with esmf/7.1.0bs35 will work on the 
upgraded Theia system.

Please let me know if you have questions or specific problems getting an 
application working on Theia since the upgrade. Thank you!


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