Hey Wow !! Here is what I found in this regard:
While it is possible to "hand tune" X to work with just about any video card and monitor, to do so is NOT RECOMMENDED. Diddling around with your clock settings, choosing a card or monitor "similar" to your equipment, or just picking horizontal and vertical synch rates at random can damage or destroy your video card or monitor. DON'T DO IT!
The optimal configuration, and the only one I can recommend, is to make sure your video card and monitor are explicitly listed and supported by X before trying to configure and run it. While I do offer some suggestions for people with unsupported hardware, there is no guarantee these suggestions will work, nor do I offer any assurance that they won't damage your equipment. Proceed at your own risk.
Full article at:
http://www.linuxgazette.com/issue33/jenkins2.html