I have a Thinkpad T520 with Nvidia Optimus. For my own sanity, I've set it (in the BIOS) to use 100% discrete graphics, so the Intel graphics are never used. There are 3 displays: The laptop's built in LCD, plus two DVI connections via a port replicator.

The problem is, when I use either the built-in monitor configuration tools, or nvidia-settings to configure my display, I'm not able to get all 3 displays to show up. Nvida-settings specifically gives me this message:

MetaMode 1 of Screen 0 has more than 2 active display devices.

I'm not sure what that means. This is with an Nvidia GF119M [Quadro NVS 4200M] (rev a1), per lspci:

01:00.0 VGA compatible controller: NVIDIA Corporation GF119M [Quadro NVS 4200M] (rev a1) (prog-if 00 [VGA controller])

        Subsystem: Lenovo Device 21cf

        Flags: bus master, fast devsel, latency 0, IRQ 16

        Memory at f2000000 (32-bit, non-prefetchable) [size=16M]

        Memory at e0000000 (64-bit, prefetchable) [size=256M]

        Memory at f0000000 (64-bit, prefetchable) [size=32M]

        I/O ports at 6000 [size=128]

        [virtual] Expansion ROM at f3080000 [disabled] [size=512K]

        Capabilities: <access denied>

        Kernel driver in use: nvidia

EDIT: Output of xrandr:

Screen 0: minimum 8 x 8, current 3840 x 1080, maximum 16384 x 16384

VGA-0 disconnected (normal left inverted right x axis y axis)

LVDS-0 connected (normal left inverted right x axis y axis)

   1920x1080      60.0 +   50.0  

DP-0 disconnected (normal left inverted right x axis y axis)

DP-1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 520mm x 290mm

   1920x1080      60.0*+

   1680x1050      60.0  

   1600x1200      60.0  

   1440x900       59.9  

   1400x1050      60.0  

   1280x1024      75.0     60.0  

   1280x960       60.0  

   1152x864       75.0  

   1024x768       75.0     70.1     60.0  

   800x600        75.0     72.2     60.3     56.2  

   640x480        75.0     72.8     59.9  

DP-2 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 521mm x 293mm

   1920x1080      60.0*+

   1680x1050      60.0  

   1440x900       59.9  

   1280x1024      75.0     60.0  

   1280x960       60.0  

   1280x800       59.8  

   1280x720       60.0  

   1152x864       75.0  

   1024x768       75.0     70.1     60.0  

   800x600        75.0     72.2     60.3     56.2  

   640x480        75.0     59.9  

DP-3 disconnected (normal left inverted right x axis y axis)

DP-4 disconnected (normal left inverted right x axis y axis)

DP-5 disconnected (normal left inverted right x axis y axis)

Another edit. This is the result of trying to use xrandr (via arandr):

$ xrandr --output VGA-0 --off --output LVDS-0 --mode 1920x1080 --pos 0x0 --rotate normal --output DP-5 --off --output DP-4 --off --output DP-3 --off --output DP-2 --mode 1920x1080 --pos 1920x0 --rotate normal --output DP-1 --mode 1920x1080 --pos 3840x0 --rotate normal --output DP-0 --off

xrandr: cannot find crtc for output LVDS-0