How much the maximum length of the array can read at a 64 system by simulink?

My system is Windows Ultimate 64-bit，the RAM of the computer is 192G.In MATLAB, the largest possible array is 182950 MB, why the simulink can just be used about 900 trillion? If I want to read more data into simulink, MATLAB will collapse. I only used the from workspace and to workspace this two easiest module. But when I try to read more data, then simulink would step in a state of compiling,therefore it could not work correctly, but at this time MATLAB does not collapse. I just want find out the reason that what lead to this question.Is it relevantto the largest available length of the array in simulink?