[MITgcm-devel] [MITgcm-cvs] MITgcm/tools/build_options CVS Commit

[Art Lazanoff]

a few additional notes:

ifort v11.1 supports -xSSE4.1 and -xHost but not earlier compilers.

Use of -xHost is interesting if and only the code is to be run on the same 
processor family (harpertown or nehalem, etc) as the code is compiled 
on. -xHost retrieves the CPUs feature set if possible. The Pleiades 
front-ends are currently Harpertown. One solution is to run a PBS job to 
compile the code.

At the moment, NAS PBS offers Harpertown queues (-q normal) and a Nehalem 
queue (-q normal_N). The next assortment of nodes is due to arrive in a few 
weeks and these are Westmeres. We'll likely have another queue forthese.

So, Dimitris, the answer to your question from earlier today about which 
CPUs you ran on can be determine by which queue you submitted the job to.

Sincerely,

Art

*****************************************************************************
Art Lazanoff                                     NASA Ames Research Center
Senior Scientific Consultant                       Mail Stop 258-6
Arthur.S.Lazanoff at nasa.gov (650) 604-1687        Moffett Field, CA 
94035-1000
*****************************************************************************

--------------------------------------------------
From: "Menemenlis, Dimitris (3248)" <Dimitris.Menemenlis at jpl.nasa.gov>
Sent: Friday, April 09, 2010 10:51 AM
To: <mitgcm-devel at mitgcm.org>
Cc: "Lazanoff, Arthur S. (ARC-AFS)[COMPUTER SCIENCES CORPORATION]" 
<arthur.s.lazanoff at nasa.gov>
Subject: [MITgcm-devel] [MITgcm-cvs] MITgcm/tools/build_options CVS 	Commit

> David, can I make SSE4.1 the default in linux_ia64_ifort+mpi_ice_nas
> with a comment that 4.2 and 4.3 is also available on some of the newer 
> processors.
>
> 4.1 is the lowest common denominator.  That way new pleiades users,
> e.g., Pierre Rampal, don't end up with cryptic error messages when
> they try to use the default optfile.
>
> Also, according to Art Lazanoff, there is probably not much speed
> up to be expected from 4.2 and 4.3 over 4.1.
>
> Let me know, Dimitris
>
>