diff --git a/md_gromacs.sh b/md_gromacs.sh
index 464d14d..334b0f9 100755
--- a/md_gromacs.sh
+++ b/md_gromacs.sh
@@ -281,7 +281,7 @@ EOF
 # Generate GROMACS .tpr file for the simulation
 run_command "Preparing MD simulation" "mpirun -np $NUM_CORES gmx_mpi grompp -f ${MDRUN_NAME}.mdp -c npt.gro -t npt.cpt -p topol.top -o ${TPR_FILE}"
 # Run the simulation
-mpirun -np $NUM_CORES gmx_mpi mdrun -deffnm ${MDRUN_NAME}
+mpirun -np ${NUM_CORES} gmx_mpi mdrun -deffnm ${MDRUN_NAME} -update gpu -ntomp 1
 # mpirun -np $(ls | egrep "Scaled[0-9]+$" | wc -l) gmx_mpi mdrun -v --deffnm md -cpi Scaled.cpt -multidir $(ls -v | egrep "Scaled[0-9]+$") -plumed plumed.dat -hrex -replex 1000 >& run_$(date "+%H%M%S_%d%m%Y").log || { echo "mdrun failed at line ${LINENO} "; exit -1; }
 # extra ndx file , select protein
 echo -e "1\nq" | gmx_mpi make_ndx -f ${MDRUN_NAME}.gro -o ${NDX_FILE}