VMD-L Mailing List

From: Rudy Richardson (rjrich_at_umich.edu)
Date: Tue Jan 31 2023 - 10:22:04 CST

I have a similar problem. I have a new workstation that has 2 x Nvidia RTX
A6000 GPUs, and I intend to order another workstation with 2 x Nvidia RTX
6000 Ada GPUs.

Thanks.

-- RJR

On Mon, Jan 30, 2023 at 10:43 PM Brendan Dennis <bdennis_at_physics.ucsd.edu>
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
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>