# GROMACS cant detect GPU (AMD)

**URL:** <https://gromacs.bioexcel.eu/t/gromacs-cant-detect-gpu-amd/11775>\
**Category:** User discussions\
**Tags:** mdrun, gpu\
**Created:** [March 20, 2025, 5:06am UTC](https://gromacs.bioexcel.eu/t/gromacs-cant-detect-gpu-amd/11775 "2025-03-20T05:06:23Z")\
**Posts on this page:** 1\
**Showing post:** 7

<div class="post-metadata">

**Author:** ![al42and](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/al42and/32/1393_2.png) [@al42and](https://gromacs.bioexcel.eu/u/al42and)\
**Post date:** [May 26, 2025, 7:18pm UTC](https://gromacs.bioexcel.eu/t/gromacs-cant-detect-gpu-amd/11775/7 "2025-05-26T19:18:21Z")

</div>

Hi!

`-DGMX_GPU_NB_CLUSTER_SIZE=8` is the correct setting for your GPU. Only Arc Alchemist and older Intel GPUs need `4`. Please rebuild GROMACS with `-DGMX_GPU_NB_CLUSTER_SIZE=8` and try again.

---

_[View the full topic](https://gromacs.bioexcel.eu/t/gromacs-cant-detect-gpu-amd/11775)._