Re: Advice on choice of NAMD to install for CUDA/GPU support

From: Axel Kohlmeyer (
Date: Mon Sep 12 2022 - 12:51:14 CDT

Three comments:

1) The error message is pretty clear:
"FATAL ERROR: QM forces are not compatible with CUDA at this time"
CUDA acceleration is only available for a subset of the NAMD functionality,
obviously not for QM/MM.

2) your GPU is pretty "wimpy". there is not much acceleration to be
expected, if any at all. best just let it do 3d graphics and be happy with

3) with QM/MM calculations the bottleneck is usually the QM code, not the
MD code. So speeding up the MD beyond parallelizing across the CPU cores (I
would not even use all of them, but leave a couple of CPU cores for other
(desktop) tasks) is not likely to cause any significant speedup.

On Mon, Sep 12, 2022 at 1:30 PM <> wrote:

> Dear All,
> I have Ubuntu 22.04 LTS installed on a Desktop PC:
> Dell Inc. Vostro 3670
> Intel® Core™ i7-8700 CPU @3.20GHz × 12 processor
> NVIDIA GeForce GT 1030/PCIe/SSE2 / NVIDIA Corporation GP108 GPU card
> NVIDIA tools installed (version 11)
> I am doing the Qwik QM/MM tutorial at
> I get it to work using a non-Cuda version of NAMD [2.14
> Linux-x86_64-multicore (64-bit Intel/AMD single node)]
> I have tried several versions of NAMD with CUDA support, but gets the
> following error when I do the QM minimization step (p15/16 of the Tutorial):
> "FATAL ERROR: QM forces are not compatible with CUDA at this time"
> The log file for this is attached. Note I have used the files provided by
> the tutorial for this calculation.
> Any help will be much appreciated.
> Best wishes
> Gert Kruger

Dr. Axel Kohlmeyer;!!DZ3fjg!8aq7Qsh6kjhH9E5d7W9lCgwyPoN2k3OGUXznZQHELYa_mZeu5Wj9bN2ktEbyGe7k78CLYuRGOV8ornmUuw$  
College of Science & Technology, Temple University, Philadelphia PA, USA
International Centre for Theoretical Physics, Trieste. Italy.

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