Charm++ parallel programming system

["Christian Tuma" <tuma AT zib.de>]

Dear Charm++ experts,

I am building NAMD (version 2.9) for our users at HLRN (www.hlrn.de). Our
system is a Cray XC30. I have downloaded Charm++ version 6.5.1 to replace
version 6.4.0 included with NAMD.

I see two different options for building charm, either

./build charm++ gni-crayxc --with-production

or

./build charm++ mpi-crayxc --with-production

What actually is the intention in the difference between 'gni-crayxc' and
'mpi-crayxc'? What is your recommended choice for Charm/NAMD on a Cray
XC30?

(I tried both these options. NAMD based on the 'gni-crayxc' version of
charm seems to be slightly more performant than with 'mpi-crayxc', but in
several cases the runs get stuck after a few minutes. The 'mpi-crayxc'
shows stable runs.)


Kind regards,
Christian Tuma

-- 
Dr. Christian Tuma
Consultant, Supercomputing
Zuse Institute Berlin, Takustr. 7, 14195 Berlin, Germany
+49 30 84185132 | 
tuma AT zib.de
 | www.zib.de