[Open-graphics] ghostbusting LCD monitors need dual-link DVI

[Dieter]

Found an interesting article that explains why LCD monitors continue
to suffer "ghosting" despite faster and faster switching times.

http://www.xbitlabs.com/articles/other/display/lcd-parameters.html

Solution appears to be adding flicker to reduce ghosting.  :-(
Keeping the flicker from being a problem will likely require
higher refresh rates, just like CRTs.  At 60 Hz, a single link
DVI can do up to 1080x1200, but with higher refresh rates,
we'll need dual-link.