Re: Replica exchange simulation with GPU Accelaration

From: Souvik Sinha (
Date: Fri Jan 26 2018 - 13:02:56 CST

Ok. Now it shines some light. I have mentioned in my earlier post that I'm
not expecting much boost from gpu for replicas. I was just checking whether
the multiple walker scheme at all has the privilage of gpu usage. I get
that launching more processes over less number of gpus is completely
useless. Earlier, with multicore-CUDA binary , single process performance
has been greatly elevated with the use of 2 gpu.

Just one question: is it because of launching 4 replicas over 2 gpu that
completely abandoned the gpu cores to work at all? I mean if I launch 2
replicas over 2 cores, will it put the gpus to work? Obviously I can check
that myself and can get back to you. Thanks again.
On 27 Jan 2018 12:03 a.m., "Giacomo Fiorin" <>

> The two multiple-walker schemes use different code. I wrote the one for
> metadynamics a few years back before NAMD had multiple-copy capability,
> using the file system. Jeff Comer and others at UIUC wrote the one for
> ABF, using the network: for this reason, its use is subject to the
> constraints of Charm++, where the simultaneous use of MPI and CUDA has so
> far been difficult.
> The network-based solution should be more scalable in large HPC clusters,
> but for a small commodity cluster of single-node replicas it should be OK--001a1147f4fe6050920563b28bcc--

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