Someone pointed out to me that it is a problem in how the mapping with newer versions is done and that using -bind-to none resolves the issue.
On Fri, Apr 10, 2015 at 3:22 PM, namu patel <namu.pat...@gmail.com> wrote: > Hello All, > > I am using OpenMPI 1.8.4 on my workstation with 2 CPUs, each with 12 > processors (6 with hyper-threading). When I run simulations using mpiexec, > I'm noticing a strange performance issue. If I run two simulations, each > with 6 processors, then everything is fine and 12 processors are under 100% > load. When I start a 3rd simulation with 6 processors, I notice throttling > in all 3 simulations and only 12 processors are at 100%, the rest are below > 10%. My guess is that somehow the processes from the 3rd simulations are > doubling onto the already busy processors. How can I be certain that this > is the case? > > Thanks, > namu >
