I think of Raw Pace as inherent pace. In terms of a car, it is how much seems to be available, with or without it being fully unlocked, for example, this years Williams.
In terms of a driver, it is the almost instinctive ability to be really quick, regardless of car, and set up. Lewis Hamilton in Canada is a good example, as was Vettels Pole lap at Valencia. I think Brogans analogy of Ronnie O'Sullivan is a good one, in that Ronnie has innate and inherent talent, and has the ability to play better snooker than any player in the history of the sport (in my opinion) and the chance he will do so is ever present. He has raw talent. When he can focus that talent, he is unbeatable.