Modify xorg.conf for better performanc

Some nice info in this.

"Most of the time, your screen's capabilities should be identified using something called EDID - Extended Display Identification Data. This is a chunk of information sent from your display to your graphics card, and normally contains information such as your screen's model and manufacturer, resolution timings and display size. X then uses this data to create appropriate resolutions and bit depths that make optimal use of your hardware."