Thank you very much for your answer. After reading Mark's very detailed posting on the topic, I played with some parameters but did not manage to get under 64K grid dimension.
On 09.09.2014 21:35, Szilárd Páll wrote:
Is this rather large box a system that can actually be simulated with a useful speed on a single Fermi GPU? Even with 5 fs time-step you won't get much more than 1-1.5 ns/day on a fast Fermi GPU like a GTX 580.
This is a rather simple toy system used for machine comparison and as a hardware reliability test. ~36nm^3 SPC water box, ~1.56x10^6 water (GTX-780 on 3770K is 0.45ns/day). I posted the question because I did not understand why this happened on the GTX-580. mdrun -nstlist x did not work (4.6.7).
Given that you are quite a bit above the limit, unless you are using a quite large nstlist, you may not be able to decrease it enough to fit the system on the GPU. What you can do instead is to use domain-decomposition and start multiple ranks per GPU. In your case two-way DD should be enough.
This sounds interesting. I'll try to accomplish that (I never thought this *this* is possible ...). Thank you very much (and Mark) Mirco -- Gromacs Users mailing list * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before posting! * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists * For (un)subscribe requests visit https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or send a mail to gmx-users-requ...@gromacs.org.
