When I run my GTX295 which has two GPUs on it only 1 cpu per gpu is pegged
at 100%
usage. If I run both GPU's I see two of my 4 cores at 100% usage in top.
~Levi
On Wed, May 26, 2010 at 3:09 PM, Jason Swails <jason.swails.gmail.com>wrote:
> Hello,
>
> Currently, multi-CPU/multi-GPU builds are not supported. i.e., if you had
> 8
> CPUs with 4 Fermi cards, you could run 4 separate pmemd.cuda simulations
> that will take up 4 CPU cores and all available GPUs. MPI and CUDA are not
> currently compatible in the amber build. There's not much need for
> multiple
> CPUs, though, since the intensive labor is done on the GPU and the CPU is
> just there to "supervise" as I see it, though others can give a better
> explanation. I think the bottleneck currently is communication off-board
> for the GPU (i.e. each time the GPU has to send information back to the CPU
> to be printed), discounting the actual calculation for a decently sized
> system (i.e. parallelizing CPUs doesn't seem worthwhile). Others may chime
> in and correct minor misconceptions I have about this, but the amber11
> release does currently only support 1 CPU and 1 GPU, and I think
> parallelization will go in the direction of making it 1 CPU for multiple
> GPUs, not the other way around.
>
> All the best,
> Jason
>
> On Wed, May 26, 2010 at 5:09 PM, Sasha Buzko <obuzko.ucla.edu> wrote:
>
> > Hi all,
> > has anyone done any comparison testing to determine the optimal number of
> > CPU cores per executing GPU?
> > I'm thinking of putting together a GPU system to run Amber. In this case,
> > would a single quad core Xeon be enough for four (4) Fermi cards (GTX480,
> > for example)? One core per card, in this case. Or should I really go for
> a
> > 2:1 ratio and a dual quad-core cpu with fewer GPUs?
> > Are there any other considerations for a multi-GPU hardware
> configuration?
> >
> > Thanks for any advice
> >
> > Sasha
> >
> >
> > _______________________________________________
> > AMBER mailing list
> > AMBER.ambermd.org
> > http://lists.ambermd.org/mailman/listinfo/amber
> >
>
>
>
> --
> Jason M. Swails
> Quantum Theory Project,
> University of Florida
> Ph.D. Graduate Student
> 352-392-4032
> _______________________________________________
> AMBER mailing list
> AMBER.ambermd.org
> http://lists.ambermd.org/mailman/listinfo/amber
>
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Received on Wed May 26 2010 - 15:30:34 PDT
