From: Josh Vermaas (
Date: Tue Jan 31 2023 - 08:58:37 CST

Hi Brendan,

I've been running VMD with CUDA 12.0 and OptiX 6.5, so I think it can be
done. I've put instructions for how to do this on github.;!!DZ3fjg!9xkQsZo2chjFAC1GOxf2-ZjwUf2rEEZS_ZGTIvgVPaSk_CmXVseH7Ru14vB-VCr8sdwhDm4ltQn_UYK7tQY$ . This set of
instructions was designed with my own use case in mind, where I have
multiple Ubuntu machines all updating from my own repository. This saves
me time on installing across the multiple machines, while respecting the
licenses to both OptiX and CUDA. There may be some modifications you
need to do for your own purposes, as admittedly I haven't updated the
instructions for more recent alpha versions of VMD.


On 1/30/23 9:16 PM, Brendan Dennis wrote:
> Hi,
> I provide research IT support to a lab that makes heavy use of VMD.
> They recently purchased several new Linux workstations with NVIDIA RTX
> A5000 GPUs, which are only compatible with CUDA 11.1 and above. If
> they attempt to use the binary release of VMD 1.9.4a57, which is built
> against CUDA 10 and OptiX 6.5.0, then they run into problems with
> anything using GPU acceleration. Of particular note is rendering an
> image using the internal TachyonL-OptiX option; the image is rendered
> improperly, with a severe checkered pattern throughout.
> I have been attempting to compile VMD 1.9.4a57 from source for them in
> order to try and get GPU acceleration working. Although I am able to
> compile against CUDA 11.2 successfully, the maximum version of OptiX
> that appears to be supported by VMD is 6.5.0. When built against CUDA
> 11.2 and OptiX 6.5.0, the image checkering still occurs on render, but
> is not nearly as severe as it was with the CUDA 10 binary release. My
> guess is that some version of OptiX 7 is also needed to fix this for
> these newer GPUs.
> In researching OptiX 7 support, it appears that how one would use
> OptiX in one's code changed pretty substantially with the initial
> 7.0.0 release, but also that CUDA 11 was not supported until the 7.2.0
> release. It additionally looks like Tachyon 0.99.5 uses OptiX 7, and I
> was able to build the libtachyonoptix.a library with every OptiX 7
> version <= 7.4.0. However, there does not appear to be a way to use
> this external Tachyon OptiX library with VMD, as all of VMD's OptiX
> support is internal.
> Is there any way to use an external Tachyon OptiX library with VMD? If
> not, is there any chance that support for OptiX 7 in VMD is not too
> far off on the horizon, perhaps even in the form of a new alpha Linux
> binary release built against CUDA 11.1+ and OptiX 7.2.0+? For now,
> I've had to tell people that they'll need to make due with using the
> Intel OSPray or other CPU-based rendering options, but I imagine
> that's going to get frustrating fairly quickly as they watch renders
> take minutes on their brand new systems, while older workstations with
> older GPUs can do them in seconds.
> --
> Brendan Dennis (he/him/his)
> Systems Administrator
> UCSD Physics Computing Facility
> <;!!DZ3fjg!6Pk3uKQJXsVVUBSNiEN5nlGSFRbvhvd-zrWzv6WpfLenvQEvVvxE_ux5Q9DAtJmubWIicqFWxYWVawU-ciHx-3E1Yw$>
> Mayer Hall 3410
> (858) 534-9415

Josh Vermaas
Assistant Professor, Plant Research Laboratory and Biochemistry and Molecular Biology
Michigan State University