Re: Running with more that 1/2 CPU'sRe: Running with more that 1/2 CPU'sHi,
If you have OpenMPI and mpi4py installed, then you have access to Gary
Thompson's multi-processor framework for MPI parallelisation. However
the code in relax must be written to support this. This is the case
for the model-free analysis, in which case Gary has achieved near
perfect scaling efficiency:
https://mail.gna.org/public/relax-devel/2007-05/msg00000.html
However for the relaxation dispersion branch, no parallelisation has
been attempted, neither in the original code from Sebastian Morin or
the recent modifications by myself. This is not a simple task and
will take a lot of effort to implement. If this is to be implemented
one day, I would suggest parallelising at the level of the spin
clusters.
Also note that it is often quite hard to achieve good scaling
efficiency and often the first attempts will just make the code
slower, even on a 1024 node cluster, due to the bottleneck of data
transfer between the nodes. The parallelisation will also require 10
times as much code to be written to do the same thing as
non-parallised code, and debugging is much more difficult. So while
it is an option, I wouldn't hold your breath for this feature. Of
course unless you have the courage to tackle such a problem yourself.
Regards,
Edward
> _______________________________________________
On 7 June 2013 12:24, Troels Emtekær Linnet <tlinnet@xxxxxxxxx> wrote:
> Hi.
>
> I have access to a computer with 24 CPU's, and want to speed things up.
>
> Architecture: x86_64
> CPU op-mode(s): 32-bit, 64-bit
> Byte Order: Little Endian
> CPU(s): 24
> On-line CPU(s) list: 0-23
> Thread(s) per core: 2
> Core(s) per socket: 6
> Socket(s): 2
> NUMA node(s): 2
> Vendor ID: GenuineIntel
> CPU family: 6
> Model: 44
> Stepping: 2
> CPU MHz: 2394.136
> BogoMIPS: 4787.82
> Virtualization: VT-x
> L1d cache: 32K
> L1i cache: 32K
> L2 cache: 256K
> L3 cache: 12288K
> NUMA node0 CPU(s): 0,2,4,6,8,10,12,14,16,18,20,22
> NUMA node1 CPU(s): 1,3,5,7,9,11,13,15,17,19,21,23
>
> I have been looking at:
> http://www.nmr-relax.com/manual/Usage_multi_processor.html
>
> This says, that you need mpi installed.
>
> Is it possible to run relax_disp in GUI mode with more than 1/2 processors?
>
> Best
>
>
> Troels Emtekær Linnet
>
> relax (http://www.nmr-relax.com)
>
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