What is the status of FMM in gromacs?

User discussions
1

GROMACS version: 2021.3
GROMACS modification: No

As the title says, following https://pubs.acs.org/doi/10.1021/acs.jctc.0c00744

But what is the trade off for say 10k atom systems?

2

There is no FFM in am official version of GROMACS yet. Where the crossover will be is unclear. Probably millions of atoms. And fewer atoms when running at extreme parallelization.