text: user7248: i'm using this command
  gmx mdrun -deffnm nvt0 -nb gpu
  
  but got
  Nonbonded interactions on the GPU were requested with -nb gpu, but the GROMACS
  binary has been built without GPU support. Either run without selecting GPU
  options or recompile GROMACS with GPU support enabled
  
  I've Nvidia rtx2060 with cuda 11.1 on ubnutu 18.4.5
  
  user3631: As the error tells you: the GROMACS binary has been built without GPU support.
  Did you install gromacs with apt-get? Usually these kind of programs are shipped with a basic built, with a lot of features disabled.
  If you did built gromacs from source, then cuda was not found during configuration.
  I would try building gromacs from source and:
  
  be sure cuda is in your path and check that nvcc and the drivers have a matching version
  run cmake and check the output, to see if the video card is recognised
  run cmake with -DGMX_GPU=ON
  
  Note that it seems that gromacs doesn't support multiple gpu accelerations( e.g. it is either openCL or cuda, you can't have both)
  
original_text: 7248: <p>i'm using this command</p>
  <pre><code>gmx mdrun -deffnm nvt0 -nb gpu
  </code></pre>
  <p>but got</p>
  <pre><code>Nonbonded interactions on the GPU were requested with -nb gpu, but the GROMACS
  binary has been built without GPU support. Either run without selecting GPU
  options or recompile GROMACS with GPU support enabled
  </code></pre>
  <p>I've Nvidia rtx2060 with cuda 11.1 on ubnutu 18.4.5</p>
   3631: <p>As the error tells you: <code>the GROMACS binary has been built without GPU support</code>.
  Did you install gromacs with <code>apt-get</code>? Usually these kind of programs are shipped with a <code>basic</code> built, with a lot of features disabled.
  If you did built gromacs from source, then cuda was not found during configuration.
  I would try building gromacs from source and:</p>
  <ol>
  <li>be sure cuda is in your path and check that <code>nvcc</code> and the drivers have a matching version</li>
  <li>run cmake and check the output, to see if the video card is recognised</li>
  <li>run cmake with <code>-DGMX_GPU=ON</code></li>
  </ol>
  <p>Note that it seems that gromacs doesn't support multiple gpu accelerations( e.g. it is either <code>openCL</code> or <code>cuda</code>, you can't have both)</p>
  