[gmx-developers] discussion of deprecation announcements in GROMACS 2021

David van der Spoel spoel at xray.bmc.uu.se
Thu Dec 10 11:46:59 CET 2020

On 2020-12-10 09:54, Mark Abraham wrote:
> Hi,
> The developers announce functionality as deprecated each year. That 
> gives users a chance to learn what changes may happen in future, so they 
> can plan how to adapt.
> I've proposed several things to deprecate at 
> https://gitlab.com/gromacs/gromacs/-/issues/3818 
> <https://gitlab.com/gromacs/gromacs/-/issues/3818> and want to encourage 
> people to consider those choices before I make an MR for the GROMACS 
> 2021 release notes.
> Often things we announce as deprecated remain that way for months or 
> years before we actually remove it. That's fine.
> The potentially controversial item is the proposed deprecation of OpenCL 
> support. We have active funded projects to implement support with SYCL 
> for Intel GPUs, and some as-yet undecided framework for AMD GPUs. When 
> those are in place, the usefulness of OpenCL as a portable approach for 
> GPU support in GROMACS has expired. We have not had the resources to 
> develop the current CUDA and OpenCL GPU code forks to the same extent, 
> and we are not going to be able to do that any better when SYCL and 
> perhaps HIP are also around. Continuing to support and test the OpenCL 
> functionality is work that we would need to do that costs us the 
> opportunity to further improve the ports we expect users to be using in 
> GROMACS 2022.
> So, when we have made enough progress on the Intel and AMD fronts, we 
> want the freedom to remove the OpenCL port, so that there's less work 
> for us to do and more freedom to adapt our GPU portability layer in the 
> directions it needs to move. I hope that will happen some time during 
> the 2021 calendar year, but it won't be January :-).
> Please feel free to discuss OpenCL here, and anything else at that 
> gitlab issue!
> Mark
The state of things with programming frameworks is rather miserable to 
say the least. From the link below I read that  HipSycl may cover both 
AMD and Nvidia GPUs. However, looking a bit closer, only the expensive 
AMD cards seem to be supported. We've been playing a bit with OpenMM 
recently that has extensive OpenCL support, and even on old laptops 
(Apple) that is a substantial improvement over using CPUs.


I guess there is no plan to abandon all the Nividia code in GROMACS for 
something else, right?

David van der Spoel, Ph.D.,
Professor of Computational Molecular Biophysics
Uppsala University.

More information about the gromacs.org_gmx-developers mailing list