It maps well to hardware from the 1970s and 1980s. It has very little to do with modern hardware, and for that matter modern hardware does some somersaults to present an interface that C "expects".
The easiest read on this topic is Chris Chisnall’s ‘C is not a Low Level Language’ article [1]. It is a good read in general and not all that long. It addresses vectors, out-of-order execution, pipelining, and plenty of other topics along the way.
