Question: I can use the nvidia drivers with my Quadro FX 1400 to drive 2 monitors, but I want to do 3 monitors, with the ability to drag windows among all of them, good expansion, etc. BTW, setting up 2 monitors is trivial. I just had to run the nvidia-settings program. But, if I use nvidia-settings to "enable" the third monitor, the machine will crash within minutes, at least with Fedora 12. The 3 monitors worked with Fedora 11, but not with 12.

Can someone point me to a recent post on someone who has done this? What video cards were used (2 cards, 1 card with 4 ports, SLI)? Did you use the proprietary or the free drivers?

Is this something than is robust enough for my everyday work machine, which must never crash, or should I just stay with 2 monitors for now?

Basically, I am looking for a tutorial on how to set up 3 or 4 monitors on a Linux machine.

Thanks!

Answer: 
If you have your video cards configured correctly in X, you could use [XRandr](http://en.wikipedia.org/wiki/RandR) to easily configure your screens. The big desktop environments should come with a GUI configuration tool, or just use `xrandr` directly on the command line. With XRandr you can change settings of a running X server (i.e. without restart).
Have you looked at [Xinerama HOWTOs](http://tldp.org/HOWTO/Xinerama-HOWTO/index.html)?