[CP2K:1732] GPGPU status

[Juerg Hutter]

Hi
>
> I am interested in the status of GPGPU code in CP2K. So far, I have
> found only the very brief mention of single precision FFT using CUDA in
> the input manual and this e-mail from the CPMD archive:
>
> http://www.cpmd.org/pipermail/cpmd-list/2008-April/004330.html
>
> Could someone please give me a brief overview of the options one has in
> this area in CP2K? I would also like to know whether there is someone
> working on some sort of GPGPU code at this time.

we have been looking into this a couple of times and also have some
accelerator cards available. Up to now we couldn't find a convincing
application, meaning a project together with a hardware setup where
the work/benefit ratio is good.

>
> I also have one more specific question. Could FFTCU be adapted to use
> double precision capable cards? I am interested in this because of
> cluster calculations in open boundary conditions, where FFT seems to be
> the main bottleneck. Also, does anyone have any experience using FFTCU?
>

we have some (but not comprehensive) experience with a setup where all
of CP2K is running double precicion except for the FFT. (compile with
-D__FFTSGL)
It seems that the loss in accuracy is not dramatic and this might be
an interesting option if a really fast single precision FFT is available.

regards

Juerg Hutter




> Thanks a lot for any replies or comments,
> Ondrej
>
> >
>