From: John Stone (johns_at_ks.uiuc.edu)
Date: Thu Apr 15 2021 - 11:23:52 CDT

Hi,
  The TachyonL-OptiX code I wrote that's in VMD will run on both GPUs
that contain RT cores (Turing, Ampere) but also on older generation
GPU hardware with general purpose SMs.

The RT performance is much higher (~5x to 8x) on GPUs containing RT cores
(Turing or Ampere generation GPUs) because they accelerate both BVH
construction and traversal, and ray-triangle intersection tests, leaving
the general purpose SMs available to do all of the shading work,
and to handle intersection tests against curved geometry, e.g.,
ray-sphere, ray-cylinder, etc.

The GPU ray tracer will still run on older hardware (it should work all the
way back to very old "Kepler" and "Maxwell" GPUs still), it just doesn't
achieve the same performance level that it does on the latest hardware.

I'm currently in the middle of a major rewrite of the TachyonL-OptiX
ray tracing engine to allow VMD to perform full-time GPU-accelerated
ray tracing as an alternative to OpenGL (in the main VMD window).
Even this new version will also support the older GPU hardware for
quite a while yet.

Best regards,
  John Stone

On Thu, Apr 15, 2021 at 04:08:29PM +0000, Jason Smith wrote:
> Correct me if I'm wrong, but ray tracing with Optix requires the ray
> tracing cores present on 2000 and later series NVidia GPUs.
>
> Cheers,
>
> -
> Jason Smith
> Post-Doctoral Fellow
> Robert N. Young Lab, Simon Fraser University
> 8888 University Drive, Burnaby, BC, V5A-1S6
> Canada
>
> --------------------------------------------------------------------------
>
> From: owner-vmd-l_at_ks.uiuc.edu <owner-vmd-l_at_ks.uiuc.edu> on behalf of John
> Stone <johns_at_ks.uiuc.edu>
> Sent: Thursday, 15 April 2021 8:20:42 AM
> To: Geist, Norman
> Cc: Nikhil Maroli; Vmd L
> Subject: Re: vmd-l: Rendering using GPU
>
> Hi,
> When VMD starts up, it automatically detects NVIDIA GPUs
> that support CUDA and OptiX (OptiX is the ray tracing development
> framework I used to write the existing lightegith GPU version of Tachyon).
> If you've got up-to-date NVIDIA drivers, you should see a VMD startup
> message
> that looks similar to this:
>
> Info) Detected 3 available TachyonL/OptiX ray tracing accelerators
> Info) Compiling OptiX shaders on 3 target GPUs...
>
> If no OptiX-capable GPUs are seen by VMD, then you won't see the
> various "TachyonL-OptiX" renderers listed in in the File->Render menu.
>
> Best regards,
> John Stone
>
> On Thu, Apr 15, 2021 at 10:45:48AM +0200, Geist, Norman wrote:
> > Use renderers with optix in their names.
> >
> > Am Donnerstag, den 15-04-2021 um 09:31 schrieb Nikhil Maroli:
> >
> > Dear All,
> > I am having 3 x 1070 with a 2 x 12 core processor. I have
> installed VMD
> > for CUDA versions. When I load VMD I can see it uses 700Mb from the
> > card, however rendering always running on the processor.
> > Can anyone tell me how I use cards for rendering purposes
> > Nikhil
> > --
>
> --
> NIH Center for Macromolecular Modeling and Bioinformatics
> Beckman Institute for Advanced Science and Technology
> University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> [1]http://www.ks.uiuc.edu/~johns/ Phone: 217-244-3349
> [2]http://www.ks.uiuc.edu/Research/vmd/
>
> References
>
> Visible links
> 1. http://www.ks.uiuc.edu/~johns/
> 2. http://www.ks.uiuc.edu/Research/vmd/

-- 
NIH Center for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
http://www.ks.uiuc.edu/~johns/           Phone: 217-244-3349
http://www.ks.uiuc.edu/Research/vmd/