From: Vermaas, Joshua (
Date: Fri Dec 06 2019 - 17:57:25 CST

Hi Yogesh,

Not a developer, but I've seen this happen if you have a cuda version that isn't supported by the driver. Then it will start normally, but specific GPU-dependent analysis and rendering routines just don't show up. What is the output of nvidia-smi? Mine looks something like this:

Fri Dec 6 16:51:55 2019
| NVIDIA-SMI 430.50 Driver Version: 430.50 CUDA Version: 10.1 |

And while you say that VMD gives no errors, I don't think anyone can say something more concrete without seeing startup output VMD spits out to the terminal.


On 2019-12-06 14:09:35-07:00 wrote:

Hello vmd developers,
We recently installed vmd-1.9.3 with cuda, OPTIX and ospray support on centos 7 systems (total 4 systems, 64 bit os, Intel Xeon, Nvidia rtx2060 and rtx2080ti) via the module system. On all systems, the latest cuda version (cuda 10.1) is installed along with the latest display driver from NVIDIA. The startup of vmd also gives no errors. However, when we attempt to ray trace the loaded molecule, the option to use Tachyon+OPTIX is simply missing from the systems. Installing the latest vmd-1.9.4 alpha build locally have the same results.
The issue that vexes us is that on an identical system with same gpus, cuda version but only ubuntu-18.04 64 bit LTS version, the Tachyon+ OPTIX/ospray works.
Can the developers please aid us in this matter to get the OPTIX ray tracing working properly?
With warm regards,