Re: How many people blame KDE Gnome but dont realise its NVidia drivers????
GTK is, compared to other toolkits,
(and depending on the engine) rather slow.
Which parts of the code (missing usage of damage, using strange methods of drawing and filling stuff) are responsible: I don't know.
But comparing gtk to qt(3) or fox or other toolkits shows it is slow. On any kind of GPU.
A nice experiment is using gtk-engines-qt, which uses qt to draw gtk elements.
Should be slower than any native gtk engine, as it is a wrapper, but is, in fact, according to gtkperf faster.