GTK is double buffered by default ? on GNU/Linux and MS Windows ?

["KLEIN Stéphane" <klein stephane gmail com>]

Hello,

I use Ubuntu system. I've showed gnome and Gimp to one friend. This friend use MS Windows since always.

He say : "I dislike Linux, Ubuntu, Gnome, Gimp ... because the GUI display scintillate. This also for Gimp MS Windows version".

He say : "First, I see the window draw, next the background draw of button...". On the contrary, MS Windows application display all widget in one step."

I don't know if you understand my subject.

My question : is there double buffering render in GTK ? If yes,  why my friend think than Windows display is faster than GTK and other widget toolkit ? If not, why that ?

Thanks for your response.
--Stéphane