[gmx-users] Cuda CC 2.0 restrictions
pall.szilard at gmail.com
Tue Sep 9 21:35:23 CEST 2014
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
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.
On Fri, Sep 5, 2014 at 11:24 PM, Mirco Wahab
<mirco.wahab at chemie.tu-freiberg.de> wrote:
> I've run into a problem with an older card (GTX-580)
> which is CC 2.0. On a larger box size, mdrun stops
> Fatal error:
> Watch out, the input system is too large to simulate!
> The number of nonbonded work units (=number of super-clusters)
> exceeds themaximum grid size in x dimension (86276 > 65535)!
> This seems to refer to the CUDA "grid of thread blocks per dimension",
> limitation specific for CC below 3.0 (I know this system worked already
> on a CC 3.0 device).
> My question: can this grid count calculated by mdrun be "manipulated"
> somehow by mdp options (nstlist, rvdw, rlist)?
> 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-request at gromacs.org.
More information about the gromacs.org_gmx-users