Re: GPU Selection in NAMD CUDA

From: Axel Kohlmeyer (
Date: Tue Sep 22 2009 - 04:39:59 CDT

On Mon, 2009-09-21 at 15:56 -0400, Ron Stubbs wrote:
> Hi All,

hi ron,

> I have a Tesla C-1060 installed on my workstation along with a Quadro
> FX
> 570 video card.
> My problem is that NAMD-CUDA is using the FX 570 instead of the Tesla
> card. Is there a way to pass an argument to NAMD-CUDA to select the
> desired device? If not guess, I'll need to download the source and
> modify it to run device 0.

you don't have to do this. the hint telling you what to do,
is in the output of the run that you have done. please see below.

> I've swapped device slots, but the Tesla still enumerated as device 0
> and the video card as device 1. NAMD-CUDA appears to look for a device
> at ID:1
> Here's the relevant excerpt for the my output file:
> Info: 1 NAMD CVS Linux-x86_64-CUDA 1
> rons
> Info: Running on 1 processors.
> Info: Charm++/Converse parallel runtime startup completed at
> 0.00278807 s
> Did not find +devices i,j,k,... argument, using all

here you are. the option to set the device to use only the
device enumerated as device 0 is: +devices 0

if you wanted to use both, you'd be using: +devices 0,1

and so on.


> Pe 0 physical rank 0 binding to CUDA device 1 on
> 'Quadro FX 570' Mem: 255MB Rev: 1.1
> Info: 1.62163 MB of memory in use based on CmiMemoryUsage

Dr. Axel Kohlmeyer 
Institute for Computational Molecular Science
College of Science and Technology
Temple University, Philadelphia PA, USA.

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