As the official site explains, GROMACS has some features that make the difference. The major advantage is that it provides extremely high performance compared to all other programs, because a lot of algorithmic optimizations have been introduced in the code.
Image: One exemple of some GPU-accelerated applications.
Theoretical and Computational Biophysics Group (NIH Center for Macromolecular Modelling and Bioinformatics)
If you want to use GROMACS software, take a look at our specialized GPU Workstations and Servers