Hello,
this behavior is normal, expected, and not a problem.
Windows computes the CPU utilization by measuring the percentage of time the CPUs are idle, then subtracting this from 100%, and report the resulting number as CPU utilization. Simulink Desktop Real-Time intentionally keeps the CPUs in non-idle state, so the response to the hardware timer event does not require waking up the CPU from idle state (which does take some small amount of time). This significantly improves real-time performance. So, the CPU utilization reported by Windows does not correspond to the real CPU utilization. Typically, there is plenty of CPU power left to run other processes. You can try to run other processes on the computer and see if there are any performance issues - there should be none.
So, you can ignore the CPU utilization reported by Windows when the real-time kernel is active, because the method used to measure it does not provide correct values in this situation.
Jan
