Hello, I have noticed that simple things like MPI_Barrier will raise my CPU usage to near 100% while waiting, and read in past emails and the FAQ that this is due to busy polling in Nemesis. As far as I can tell, the one solution usually offered to reduce this CPU usage is reconfiguring with sockets instead of Nemesis. I would also like to use the MPI_THREAD_MULTIPLE feature, but I read that the socket channels don't support it, and it would be annoying to have to recompile MPICH to get one benefit or the other. I was just wondering if recent advancements invalidated some of the above and officially ask what the options are for reducing the CPU usage of MPICH during barriers. Thank you, _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss