From owner-chemistry \\at// ccl.net Thu Jul 31 06:29:00 2008 From: "Herbert Fruchtl herbert.fruchtl^st-andrews.ac.uk" To: CCL Subject: CCL:G: Duel cords processors and parallel calculations Message-Id: <-37462-080731062421-30836-YpK7RNyHx3aM20g4Qj8CPA[]server.ccl.net> X-Original-From: Herbert Fruchtl Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8; format=flowed Date: Thu, 31 Jul 2008 10:54:17 +0100 MIME-Version: 1.0 Sent to CCL by: Herbert Fruchtl [herbert.fruchtl#,#st-andrews.ac.uk] It would help to know WHAT you want to do in parallel. To use several cores at the same time, you need to 1) Write the program for parallel execution 2) Compile the program for parallel execution 3) Run it in parallel. If you have a parallel executable, i.e. 1) and 2) are taken care of, this leaves you with 3), which depends on the parallelization method (and the operating system). - If it's Gaussian, you need %NProcShared=2 in the input. - If it's another OpenMP program, you have to set the environment variable OMP_NUM_THREADS (it depends on the OS how you do that). - If it's an MPI program, you need to run it via a parallel startup program (in most implementations this is called mpirun, but the syntax may vary. RTFM!). - If it's yet another parallelization method (PVM, GA, ...), RTFM! But since anybody who can't be bothered to mention his program is using Gaussian anyway... Herbert may abdelghani may01dz*|*yahoo.fr wrote: > dear CCLers, > In any calculations, a duel core processors, using only one core for > this calculation, whereas the second rest inactive. I ask if it is any > possibility to help the tow cores of my processor to sharing a one > calculation, like what we do in the parallel calculations (both cores do > a one task in the same time). > Thanks > > > > > > > > > ------------------------------------------------------------------------ > Envoyé avec Yahoo! Mail > . > Une boite mail plus intelligente. -- Herbert Fruchtl EaStCHEM Fellow School of Chemistry University of St Andrews -- The University of St Andrews is a charity registered in Scotland: No SC013532