Originally Posted by AaronP
There may be some confusion here. RandR 1.2 and the Xinerama extension (the real one that glues together multiple X screens) aren't compatible with each other. The RandR 1.2 code has its own implementation of the Xinerama extension (which some people refer to as, "Fakerama"), which it uses to report the position of the CRTCs to clients. This is similar to the X driver's TwinViewXineramaInfo option.
Nope no confusion, I am fully aware of that. My test today was specifically to test if the new XRandR 1.2's internal "fakerama" worked with the NVidia drivers. I disabled `Option "Xinerama"` in my "Server_Layout" section in xorg.conf before doing the tests. The point is that because the traditional Xinerama option in xorg.conf disables XRandR you can't use a composite window manager, with the new 1.2 specification handling Xinerama internally, there will be no need to use the `Option "Xinerama"` setting in xorg.conf and therefore XRandR won't be disabled and the user will be able to run a composite window manager and still be able to use a Xinerama type setup by allowing XRandR 1.2 to handle it for them.