Hi, I have a code that looks like this: while(true) { do some I/O (HDF5 POSIX output to a remote, parallel file system) wait for communication (MPI_Waitany) from other processes (in the same node and outside the node) } I'm measuring the energy consumption of the node that runs this process for the same duration, as a function of the amount of data written in each I/O operation. Surprisingly, the larger the I/O in proposition to the communication, the lower the energy consumption. In other words, the longer I wait in MPI_Waitany, the more I consume. Does anyone have a good explanation for that? Is there an active loop in MPI_Waitany? Another reason? Thanks! Matthieu _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss