Why does surf print image to screen so much faster than contourf?

Hello, I'm trying to plot a large data set using contourf, but it takes an extremely long time just to show up on my screen. I use surf and it prints to the screen very quickly, however it doesn't render as well. I was wondering why this might be>

Answer 1

[Nicolas Schmit]

Probably because contourf() has to slice the dataset to calculate the coordinates of the contours plots, whereas surf() can directly plot the surface from the coordinates.