VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Wed Oct 10 2018 - 10:21:13 CDT

Hi Pawel,
  I'll address the RTX and Turing parts of your question separately
since they're independent but related topics.

RTX refers to the new ray tracing acceleration (thus the 'R', 'T', 'X')
hardware found in Turing and subsequent RTX-capable GPUs. Presently,
the only part of VMD that will benefit from RTX are the TachyonL-OptiX
rendering engines built-into VMD.
The RTX hardware I've benchmarked to date can give VMD as much as
6x to 8x performance gain when compared with the previous Volta GPU hardware,
and Volta was (I forget, maybe 1.3x?) faster than previous Pascal hardware.

I've been testing pre-production RTX GPU hardware and RTX-enabled OptiX
and driver software since early August. That said, there have been
some unforeseen delays in the availability of public versions
of some of the RTX software components that VMD uses, which are going
to delay the availability of RTX-enabled VMD builds to at least the
end of this year, so I am now planning on releasing the non-RTX VMD 1.9.4
builds after a short beta testing period. Once the RTX software components
from NVIDIA can be made publicly available, I will then release RTX-enabled
VMD 1.9.4 builds and/or a new version of VMD that adds further RTX features
beyond what I have built-into VMD 1.9.4 today. The VMD 1.9.4 source code
already contains RTX support, so my expectation is that as soon as
NVIDIA makes the software components publicy available, anyone would
be able to build RTX-enabled VMD binaries from the source.

With regard to the non-RTX features of Turing as compared with Pascal,
I think that the greatest advances in Turing for general purpose use
in VMD are the increased memory bandwidth (~600 GB/sec, GDDR6)
and increase arithmetic throughput. There is an informative set
of tabulated performance data available in the Turing White Paper here:
  https://www.nvidia.com/content/dam/en-zz/Solutions/design-visualization/technologies/turing-architecture/NVIDIA-Turing-Architecture-Whitepaper.pdf

The Turing hardware has much better integer arithmetic performance than any
GPU NVIDIA has made to date, so I'm expecting it to perform very well
on some of VMD's CUDA-accelerated cryo-EM density map processing algorithms,
e.g. image segmentation, cross-correlation, rigid body fitting of structures
with maps, and general density map manipulation operations.

Down the road further when we start getting OpenXR and native
HMD support into VMD, I expect that the special single-pass stereoscopic
rendering features of Turing will become very beneficial for using
VMD with VR HMDs. I believe that those features are also described
in the architecture white paper document PDF above.

Best regards,
  John Stone
  johns_at_ks.uiuc.edu

On Wed, Oct 10, 2018 at 10:55:13AM +0200, Pawel Kedzierski wrote:
> Dear All,
>
> I'm about to buy new hardware and I'm already aware that the new VMD
> will support real-time raytracing (aka RTX) on Turing GPUs, as
> announced in this message:
> https://www.ks.uiuc.edu/Research/vmd/mailing_list/vmd-l/30255.html
>
> Are there any other advantages of the new Turing GPUs for VMD use
> and CUDA calculations, in comparison to Pascal? As my budget is
> fixed I want to make an fair balance between number of cores, RAM
> and GPU capability.
>
> Thank you,
>
> Pawel
>

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> email;internet:Pawel.Kedzierski_at_pwr.edu.pl
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> tel;fax:+48 71 3203364
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> 

-- 
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/