Automatic Solver Option
Starting with R2015b, you can use the auto solver to select a solver and step size for simulating a model. The auto solver suggests a fixed-step or variable-step solver along with maximum step size based on the dynamics of the model. Select the auto solver in the solver pane and accept recommended settings in the solver information dialog box.
You can also select a web site from the following list:
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.