  Dissipative particle dynamics is a widely used mesoscale technique for the
simulation of hydrodynamics (as well as immersed particles) utilizing
coarse-grained molecular dynamics. While the method is capable of describing
any fluid, the typical choice of the friction coefficient $\gamma$ and
dissipative force cutoff $r_c$ yields an unacceptably low Schmidt number $Sc$
for the simulation of liquid water at standard temperature and pressure. There
are a variety of ways to raise $Sc$, such as increasing $\gamma$ and $r_c$, but
the relative cost of modifying each parameter (and the concomitant impact on
numerical accuracy) has heretofore remained undetermined. We perform a detailed
search over the parameter space, identifying the optimal strategy for the
efficient and accuracy-preserving scaling of $Sc$, using both numerical
simulations and theoretical predictions. The composite results recommend a
parameter choice that leads to a speed improvement of a factor of three versus
previously utilized strategies.
