How to frequently trigger a MEX function as fast as possible?

Hi,

first time post. I'm implementing a interprocess communication between Simulink and a WPF application. I'm already using a TCP approach (using Googles GRPC Protocol) to communicate inbetween both. This works very stable, but is obviously not the fastest implementation. For a faster transmission of signal values, I have implemented an adapter to Shared Memory within a custom C (MEX) extentions.

The Problem:

I need to trigger my MEX adapter as often as possible (~15 ms/60Hz). The operation/callback is very fast! It collects the port values from the Runtime object and sends them over to the memory. The MEX adapter needs below 1 ms for 500 signals on my rather "slow" laptop while a simulation runs. In practise I deal with 30 signals, so its a matter of Microseconds for the whole operation! (Performance was measured with the timeit function under load)

In order to do so I have implemented 4 different ways:

1. Matlab timer in various settings -> Set to 15ms but fires at 100+ms (too slow) . I don't know why...
2. add_exec_event_listener -> Fast enough, but does not work in Accelerated Mode and on Simulationstate Idle; Requires a Block to listen which overcomplicates everything.
3. C++ (MEX) Timer in various implementations -> evalAsync seems to slow down. It performs a bit slower than a Matlab timer
4. Multiple Matlab timer, firing in chain. Works faster than using a single Matlab timer, but I'm still unable to reach 15 ms

Me and my clients are using Matlab 2019b (Windows).

Now, is there anyway I can trigger everything faster under any circumstances? Isn't it possible to invoke on the main thread properly, without any overhead? Why does add_exec_event_listener is so fast, but the timer fails to keep up? I ran out of ideas... :(

Any help is appreciated!