Well, yes and no. Besides the real question would be if this app, which this 
person didn't write, was written as a threaded application.

On Jun 16, 2014, at 8:32 PM, Zehan Cui <zehan....@gmail.com> wrote:

> Hi Yuping,
> 
> Maybe using multi-threads inside a socket, and MPI among sockets is better 
> choice for such NUMA platform. 
> 
> Multi-threads can exploit the benefit of share memory, and MPI can alleviate 
> the cost of non-uniform memory access.
> 
> 
> regards,
> Zehan
> 
> 
> 
> 
> On Tue, Jun 17, 2014 at 6:19 AM, Yuping Sun <yupingpaula...@att.net> wrote:
> Dear All:
> 
> I bought a 64 core workstation and installed NASA fun3d with open mpi 1.6.5. 
> Then I started to test run fun3d using 16, 32, 48 cores. However the 
> performance of the fun3d run is bad. I got data below:
> 
> the run command is (it is for 32 core as an example)
> mpiexec -np 32 --bysocket --bind-to-socket 
> ~ysun/Codes/NASA/fun3d-12.3-66687/Mpi/FUN3D_90/nodet_mpi --time_timestep_loop 
> --animation_freq -1 > screen.dump_bs30
> 
> CPUs     times    iterations    time/it
> 60    678s    30it        22.61s
> 48    702s    30it        23.40s
> 32    734s    30it        24.50s
> 16    894s    30it        29.80s
> 
> You can see using 60 cores, to run 30 iteration, FUN3D will complete in 678 
> seconds, roughly 22.61 second per iteration.
> 
> Using 16 cores, to run 30 iteration, FUN3D will complete in 894 seconds, 
> roughly 29.8 seconds per iteration.
> 
> the data above shows FUN3D run using mpirun does not scale at all! I used to 
> run fun3d with mpirun on a 8 core WS, and it scales well.
> The same job to run on a linux cluster scales well.
> 
> Would you all give me some advice to improve the performance loss when I 
> increase the use of more cores, or how to run mpirun with proper options to 
> get a linear scaling when using 16 to 32 to 48 cores?
> 
> Thank you.
> 
> Yuping
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
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