[Pw_forum] On the run of GPU version of QE

[Filippo Spiga]

Dear Alexander,

On Mar 25, 2014, at 5:29 AM, Alexander G. Kvashnin <agkvashnin at gmail.com> wrote:
> Dear QE users and developers,
> 
> Recently I compiled QE-GPU on my system with GPU NVidia Tesla K20Xm.
> I have CUDA ver. 5.5.
> Intel MPI 4.1.3.048
> Intel Compiler 14.0
> 
> I compiled GPU-QE using the instruction on the website. I downloaded espresso-5.0.2, than downloaded QE-GPU-14.01.0 with patch file. After the patching I type a configuration command:
> 
> ./configure  LAPACK_LIBS=/opt/intel/composer_xe_2013_sp1.2.144/mkl/lib/intel64/libmkl_lapack95_lp64.a --enable-openmp --enable-parallel --enable-cuda --with-gpu-arch=30 --with-cuda-dir=/opt/cuda/5.5  --enable-phigemm --enable-magma

"--with-phigemm" and "--with-magma" are the correct. i will add a check that, if someone spell those wrong, the configure step will halt completely. I am going to check the website and the README too to verify there is consistency in the instructions.

I do suggest to do _not_ specify any BLAS/LAPACK/SCALAPACK variable in the configure line but edit the make.sys after!



> After successful configuration I compile pw-gpu.x and everything was fine. Then I tried to test the performance of this system compared with common HPC. 
> But I have troubles. As I understand commonly 1 process goes to 1GPU, so I need to run 2 MPI processes on my host with 2 GPUs. If I am wrong, please, tell me where? After the start I have the error message:
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>     task #         0
>     from cdiaghg : error #        61
>     diagonalization (ZHEGV*) failed
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Probably because MAGMA is used (there should be a message on top of the output). Next version will print a lot of information on top of the file so it is possible to understand how the application has been compiled and what features are active.

Can you try recompiling using "--without-magma"?

Thanks
F

--
Mr. Filippo SPIGA, M.Sc.
http://www.linkedin.com/in/filippospiga ~ skype: filippo.spiga

«Nobody will drive us out of Cantor's paradise.» ~ David Hilbert

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