Re: Regarding Files-in-Memory (FiM) feature in Molcas 8.0


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Posted by Steven Vancoillie on September 10, 2015 at 09:31:54:

In Reply to: Re: Regarding Files-in-Memory (FiM) feature in Molcas 8.0 posted by Mariusz Radon on July 09, 2015 at 16:40:59:

Hi Mariusz

: Indeed, it is all about Molcas installation on a system with LUSTRE scratch. I observed very slow execution of rasscf (>10 time slower than expected!), until our administrator recommended me to turn on I/O buffering for the Intel compiler (FORT_BUFFERED=true) and suggested also to play with FiM. Which is what I am struggling against now...

I recently (february, version 8.1) ported the I/O in lucia (part of rasscf) from Fortran to our own Molcas I/O routines which use underlying C functions. So in Molcas 8.2 this should be remedied.

: Is there anything else worth trying to speed-up Molcas on a lustre filesystem (serial installation only)?

Not really, you either need local scratch or plenty of memory. Another alternative for FiM could be to create a RAM disk for the work directory.

grtz
Steven



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