Hi Tom, Thank you.
I haven't still changed my code to run when threading is needed (presently working). I have doubt that when i calculate the MPI ranks using the MPI command it gives only the nodes which have given in a host file. But how can i calculate the MPI ranks as you have told i.e N=H( number of CPUs showing on a node ) x M ( number of nodes in a cluster). And I would like test like this if have 2 nodes and where I can use up to 50 cores. I would like to scale like 2,4,8,16,32,45 cores and at the same time if use 8 cores then I would like to take the readings as node1- 3cores and node2-5 cores. So in order to do that should I need mention anything in the host file as I have mentioned the No.of nodes. And can provide me any tutorials which explains with an example programs. Thanking you, On Mon, Aug 13, 2012 at 6:59 PM, Elken, Tom <tom.el...@intel.com> wrote: > Hi Seshendra,**** > > ** ** > > If you have implemented hyperthreading by Enabling it in the BIOS, then > when you look at**** > > cat /proc/cpuinfo output, you will see 2x the # of CPUs than the number of > cores on your system. **** > > If that number of CPUs showing on a node = H, and the number of nodes in > your cluster with this same configuration is M, **** > > Then you can run your program on up to N = H x M MPI ranks,**** > > and your Open MPI mpirun command can use the**** > > ‘-np N –npernode H’ options to indicate this.**** > > ** ** > > Note that with some applications, you may see very little benefit to > hyperthreading. In any case, you should also run on “-np N/2” ranks and > add the “-npernode H/2” setting to not use more ranks per node than you > have cores per node, and compare performance with N ranks (with H per node). > **** > > ** ** > > -Tom**** > > ** ** > > **** > > ** ** > > *From:* users-boun...@open-mpi.org [mailto:users-boun...@open-mpi.org] *On > Behalf Of *seshendra seshu > *Sent:* Monday, August 13, 2012 9:27 AM > *To:* Open MPI Users > *Subject:* [OMPI users] Regarding hyperthreding**** > > ** ** > > Hi,**** > > I have written an code mpi and an iam trying to implement hyperthreading > environment. So could any one tell me how to implement and run the > program in open mpi.**** > > ** ** > > Kindly help me.**** > > ** ** > > Thanking you,**** > > ** ** > > ** ** > > > -- > WITH REGARDS > M.L.N.Seshendra**** > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users > -- WITH REGARDS M.L.N.Seshendra
