Quetions about performance

GROMACS version:2021
GROMACS modification: No
I did umbrella tutorial with my protein complex ( protease-inhibitor ).
I had follow final message:
gmx mdrun -deffnm umbrella22
Reading file umbrella22.tpr, VERSION 2021 (single precision)
Changing nstlist from 20 to 100, rlist from 1.417 to 1.533
Using 24 MPI threads
Using 1 OpenMP thread per tMPI thread
starting mdrun ‘Protein in water’
5000000 steps, 10000.0 ps.
Writing final coordinates.
Dynamic load balancing report:
DLB was off during the run due to low measured imbalance.
Average load imbalance: 0.2%.
The balanceable part of the MD step is 89%, load imbalance is computed from this.
Part of the total run time spent waiting due to load imbalance: 0.2%.
Average PME mesh/force load: 0.397
Part of the total run time spent waiting due to PP/PME imbalance: 9.4 %
NOTE: 9.4 % performance was lost because the PME ranks
had less work to do than the PP ranks.
You might want to decrease the number of PME ranks
or decrease the cut-off and the grid spacing.

           Core t (s)   Wall t (s)        (%)
   Time:  1103697.060    45987.378     2400.0
             (ns/day)    (hour/ns)

Performance: 18.788 1.277

And now, these performance are ok ? Can I get improve my machine work ?

Have you read the relevant parts of the user guide?

What run parameters have you tested?