Why does n++ execute faster than n=n+1?

Question

In C language, Why does n++ execute faster than n=n+1?

(int n=...;  n++;)
(int n=...;  n=n+1;)

Our instructor asked

Answer 1

I think it's more like a hardware question rather than software... If I remember corectly, in older CPUs the n=n+1 requires two locations of memory, where the ++n is simply a microcontroller command... But I doubt this applies for modern architectures...