Yeah, it looks like maybe font kerning is slow? I don't know. The results on my laptop with Ubuntu Sans vs. Ubuntu Mono are even more insane though:
GtkTextView - Add text - time: 33.74
GtkTextView - Add text - time: 5.15
Makes me think it might be worth switching to monospace fonts for most widgets on slower machines, if you can find ones that are easily readable. Those differences will add up.
Edit: what's more interesting is that appending the text slows down drastically as the amount of previous text increases. Not sure if that's a GTK2 problem, or a problem with the gtkperf program; I think it smacks a bit of data structure issues...
Last edited by Gullible Jones; 03-21-2014 at 10:32 PM.