Hi all, I have OF installed
 

Hi all,

I have OF installed with both sp and dp. Therefore I change the environment and recompile everything a second time with the other precision. This works but gives me everything twice. Is this essential?
Additionally I am planing to use a second mpi implementation (thinging of MPIGamma). Does this mean four installations now? (sp/dp for both of the mpis) Or is there another way to switch mpi implementation? Thanks.

BastiL

Anything that uses 'scalar' in
 

Anything that uses 'scalar' in the source code needs recompilation. There is no need to recompile openmpi if you switch precision.

If you use a second mpi implementation you'll need to recompile the Pstream library so you'll have two (SP and DP) of all OpenFOAM libraries and 4 libPstream.so.

Try Open-MX (http://gforge.inria.fr/projects/open-mx/) instead of MPIGamma. Please post some results if you are successful.

I did not get that. So far I r
 

I did not get that. So far I recompile ALL aplications for sp. First I compile everything in dp and afterwards in sp. So I get every application twice and have the choice running it in sp or dp.
Obviously this is not esential? Where can I find out what needs scalar?

I will try Open-MX and keep you up. Is this your new favourite instead of GAMMA?

Regards.

Yes it is essential to compile
 

Yes it is essential to compile everything OpenFOAM in single and double precision. There is no need though to compile OpenMPI in single or double precision.

We haven't compiled the GAMMA driver for a while. Open-MX should be much easier to install (no kernel patching) and works alongside normal ethernet traffic so you don't need a separate network as you do for GAMMA.

Sorry for the delay I just sta
 

Sorry for the delay I just started looking into it.
Building Open-MX is no problem. However I do not really understand how to use it. As far as I understand I need to use OpenMPI as a middleware. I tried to rebuild the OpenFOAM 1.2.6-openmpi with mx-support using the open-mx driver. However, this failed. I am not sure if this is the way it is supposed to run....

Regards BastiL

Yes, you will need Open-MX com
 

Yes, you will need Open-MX compatible middleware, ie. an MPI implementation with a backend that supports the Open-MX library.

http://open-mx.gforge.inria.fr/

Thanks Martin, as far as I
 

Thanks Martin,

as far as I understand OpenMPI should do this, right? However I do not understand how to do? Is it essential to rebuild OpenMPI with OpenMX-Support as it is for MX-Support? (I use the 1.26 delivered with OpenFOAM 1.5). If yes, how to do that. If not, how do I use OpenMX with OpenMPI middleware? I have not found any documentation about that.

Regards.

I am an MPICH2 man myself, and
 

I am an MPICH2 man myself, and have never used OpenMPI, so I cannot give you a definitive answer. However, I would expect you'd have to build/rebuild OpenMPI with support for MX, by specifying where the OpenMX header files and libraries are located.

Most likely this is done with a command line switch when running configure. I.e. something like

./configure --with-mx=<path>

You will have to consult a "how to build OpenMPI" site for the details.

Yes thats what I tried to do.
 

Yes thats what I tried to do. However OpenMPI does not build taht way against Open-MX but it does against MX.

Look in your configure result
 

Look in your configure result file. Does it indicate that it will build with MX support using your Open-MX install?

Maybe this can be of some help also:

http://www.open-mpi.org/faq/?categor...ding#build-p2p

Thanks, I was aware of this. I
 

Thanks, I was aware of this. It works now. The problem was that "make install" of Open-MX had not been performed. Now everything works fine.

BastiL