Multiple windows or multiple framebuffers for UI?

I’m thinking about the GUI of my application. It consists of three or four larger areas, one main part with the graphical output, one UI part for element selection and one for parameter editing. The parts do not need to be translated, scaled or moved independently from each other.

Does anyone has experience with the implementation of such a GUI, is it more useful to use multiple framebuffers or should I use multiple windows because they can work independently and would not overload the main application with too many UI callbacks?