You can turn off automatic updates of panes in the Simulation window by clicking 
. Turning off auto-updates of panes will cause all of the panes (Sessions, Console, Variables, and Breakpoints) in the Simulation window to be disabled and the simulation speed to increase. This can be seen in the comparison of the Simulation window before turning off the auto-update option and after turning off the auto-update option in the following figures respectively.
The following figure shows when the auto-update of panes is enabled
The Simulation window of the Calculator.mdzip sample with the auto-update of panes option is enabled.
The following figure shows when the auto-update of panes is disabled
The Simulation window of the Calculator.mdzip sample with the auto-update of panes option is disabled.
After the auto-update of panes option is disabled, you can work on the model, make changes, or run it, but the actions that you are performing will not be displayed in any of the panes in the Simulation window. If you enable the option, the Actions that you have performed will appear in the panes.