Re: Emacs GTK scroll-bar flickering

[Richard Stallman]

    BTW, I find that I can get better scrolling behavior with emacs/GTK if I
    set `redisplay-dont-pause' to t -- otherwise, if I e.g., hold down a
    scroll key (say C-v), scrolling updates the scroll bar smoothly, but the
    text window only gets updated when I stop scrolling.  Any comment on
    this?  [My processor seems to be fast enough to keep up when
    redisplay-dont-pause is t]

Does redisplay do a better job of keeping up when Emacs doesn't use
GTK?  If so, it suggests that redisplay with GTK is much slower.
The thing to do is investigate what is taking the time.