What can cause long simulations times with large "self time" in Simulink Profiler for models or model references.

I have a model that simulates slowly. My model has many signals, many of them multidimensional or bus signals. When I simulate with Simulink Profiler, it does not show one clear block that is causing problems. Much of the time is "self time" in the model itself or model references. What could be causing this?

Answer 1

[MathWorks Support Team]

This could be time Simulink spends on diagnostics such as "Simulation Range Checking" and "Inf or NaN block output". Try disabling some of the run-time diagnostics that scale with the number of signals and see if that improves performance.

Model Configuration Parameters: Data Validity Diagnostics - MATLAB & Simulink (mathworks.com)

Also inspect the number of warnings being thrown by your model. Throwing warnings can be expensive and blocks simulation execution. If you have hundreds or thousands of warnings, consider addressing the root issue or disabling diagnostics to reduce them. 

Both running diagnostic checks and throwing warnings are two common reasons for "self time" to be large but not the only ones. If you need additional assistance locating the root cause of large "self time" for a model, consider creating a case with MathWorks Technical Support.