[gmx-users] Re: GLOBAL ARRAYS

[Srirangam Addepalli]

If i was trying to run some benchmarks for GROMACS on a AMD cluster
and i realised that when i wanted to run a 4 processor mpi job i was
not
getting very good speed up. I was under the impresssion that Global
Arrays provide a efficient and portable shared memory programming
interface for distributed memory computers. as i have not tried a job
yet which request more than 2 GB of memory my initial question does
not make sense. Rather i would ask it this way

Are there jobs which request 2-6GB of memory, the primary objective is to
test the performace on a itanium and opteron which have different bus
architecture for memory modules.

Sincerly

Rangam 

Message: 4
Date: Thu, 12 Aug 2004 11:40:30 +0200 (CEST)
From: David van der Spoel <spoel at xray.bmc.uu.se>
Subject: Re: [gmx-users] GLOBAL ARRAYS GROMACS
To: Discussion list for GROMACS users <gmx-users at gromacs.org>
Message-ID:
       <Pine.LNX.4.44.0408121139230.18913-100000 at rembrandt.bmc.uu.se>
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Wed, 11 Aug 2004, Srirangam Addepalli wrote:

>Hello All,
>            Has any one ever tried implemeting global array for gromacs.
>Sicerly
can you expand on this?
do you mean a global array in parallel version of the code?
we are trying to make things more local, global arrays have large overhead
on distributed memory machines.

>
>Rangam