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
