From Fedora Project Wiki

To get the native resolution working on each monitor I had to create an xorg.conf like this when using the live CD:

Section "Device"
	Identifier "Videocard0"
	Driver "nouveau"
EndSection

Section "Screen"
	Identifier "Screen0"
	SubSection "Display"
		Depth 24
		Virtual 3000 2000
	EndSubSection
EndSection


This is my xrandr after using the the above config:

Screen 0: minimum 320 x 200, current 2960 x 1050, maximum 3000 x 2000
DVI-I-0 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm
   1680x1050      59.9*+
   1400x1050      60.0  
   1280x1024      75.0     60.0  
   1280x960       60.0  
   1152x864       75.0  
   1024x768       75.0     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        75.0     72.8     75.0     66.7     59.9  
   720x400        70.1  
DVI-I-1 connected 1280x1024+1680+26 (normal left inverted right x axis y axis) 338mm x 270mm
   1280x1024      60.0*+   75.0     60.0* 
   1280x960       60.0  
   1152x864       75.0  
   1024x768       85.0     75.0     70.1     60.0  
   832x624        74.6  
   800x600        85.1     85.1     72.2     75.0     60.3     56.2  
   640x480        85.0     75.0     72.8     75.0     66.7     59.9  
   720x400        85.0     70.1  
   640x400        85.1     70.0  
   640x350        85.1