# Milstein scheme for Heston model - rate of convergence

Heston model is described by following SDE \begin{aligned} dS_t &= \mu S_t dt + \sqrt{\nu_t} S_t dW^S_t \\ d\nu_t &= \kappa(\theta - \nu_t) dt + \xi \sqrt{\nu_t} dW^{\nu}_t \\ \textrm{Corr}[W^S_t, W^{\nu}_t] &= \rho \end{aligned}

If I use Milstein scheme for $$\nu _t$$ and $$S_t$$, what will be the rate of convergence of process $$S$$ (when I compare results with denser mesh)? Is it $$1.0$$ or no?