Yes, it is -- sometimes we get so caught up in other issues that user emails slip through the cracks. Sorry about that!
I actually have little experience with EC2 -- other than knowing that it works, I don't know much about the performance that you can extract from it. I have heard issues about non-uniform latency between MPI processes because you really don't know where the individual MPI processes may land (network- / VM-wise). It suggests to me that EC2 might be best suited for compute-bound jobs (vs. latency-bound jobs). Amusingly enough, the first time someone reported an issue with Open MPI on EC2, I tried to submit a help ticket to EC2 support saying, "I'm one of the Open MPI developers ... blah blah blah ... is there anything I can do to help?" The answer I got back was along the lines of, "You need to have a paid EC2 support account before we can help you." I think they missed the point, but oh well. :-) On Mar 12, 2010, at 12:10 AM, Hammad Siddiqi wrote: > Dear All, > Is this the correct forum for sending these kind of emails. please let me > know if there is some other mailing list. > Thank > Best Regards, > Hammad Siddiqi > System Administrator, > Centre for High Performance Scientific Computing, > School of Electrical Engineering and Computer Science, > National University of Sciences and Technology, > H-12, Islamabad. > Office : +92 (51) 90852207 > Web: http://hpc.seecs.nust.edu.pk/~hammad/ > > > On Sat, Feb 27, 2010 at 10:07 PM, Hammad Siddiqi > <hammad.sidd...@seecs.edu.pk> wrote: > Dear All, > > I am facing very wierd results of OpenMPI 1.4.1 on Amazon EC2. I have > used Small Instance and and High CPU medium instance for benchmarking > latency and bandwidth. The OpenMPI was configured with the default > options. when the code is run in the cluster mode the latency and > bandwidth of Amazon EC2 Small instance is really less than that of > Amazon EC2 High CPU medium instance. To my understanding the > difference should not be that much. The following are the links to > graphs ad their data: > > Data: http://hpc.seecs.nust.edu.pk/~hammad/OpenMPI,Latency-BandwidthData.jpg > Graphs: http://hpc.seecs.nust.edu.pk/~hammad/OpenMPI,Latency-Bandwidth.jpg > > > Please have a look on them. > > Is anyone else facing the same problem. Any guidance in this regard > will highly be appreciated. > > Thank you. > > > -- > Best Regards, > Hammad Siddiqi > System Administrator, > Centre for High Performance Scientific Computing, > School of Electrical Engineering and Computer Science, > National University of Sciences and Technology, > H-12, Islamabad. > Office : +92 (51) 90852207 > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
