my simulation is very slow

hi, could any one help me please? actually, i am using Matlab 2017a , it was ok, but after I had formatted my laptop and reinstall it again, the simulation became very slow, although I am using the same version that I used before in run the same model which was fast

[Matt J]

My guesses would be,

(1) You think you're running the same version of the code, but you're not.

(2) You think you're running it on the same data, but you're not.