Linux graphics drivers from Intel

http://www.intellinuxgraphics.org/dualhead.html
How to setup Dual Head for Intel Graphics with RandR 1.2

1. Introduction

This guide is targeted for people who want to use extended desktop mode on two outputs. Clone mode should work out-of-box with a normal configuration.

With RandR 1.2, you can setup dual head and add/remove monitor dynamically (i.e. on-the-fly, without restarting X).

To use RandR 1.2, you might need to know three key concepts: (Virtual) Screen, Crtc and Output. A display is in one (Virtual) screen which may consist of more than one Crtc. Every crtc will occupy one rectangle region in the (Virtual) screen and may have different modes. A crtc can connect to more than one output and decide the output's property. Output is a port to monitor.

Intel GFX device supports two pipes which is corresponding to crtc. So there can be two crtc with Intel GFX device.

Prerequisite: To use randr1.2, xserver 1.3 or above is required. And for Intel gfx driver, xf86-video-intel 2.0.0 or above is required.

Note: After the driver moving to Kernel Mode Setting, the name of output is changed (e.g. from LVDS to LVDS1).