Originally Posted by _john_i_
I also wonder if such a twinview configuration were possible how subpixel font smoothing would work. Since X sees twinview as a single screen, the horizontal monitor would need RGB pixel order antialiasing, but the vertical monitor would need VRGB, or the fonts would look weird. You'd have to switch to uglier grayscale antialiasing.
AFAIK gnome supports VRGB antialiasing