Triple-head on a Lenovo T520

With Optimus enabled and OS detection on in the BIOS, I've got 2 external DVI connected monitors (docking - Nvidia card) and the laptop LCD (Intel card) to work. I did also get the VGA (Intel card) on the docking working, but was not able to not have it as a clone of the laptop LCD.

Here is my xorg config with Xinerama enabled:

Section "ServerLayout"
    Identifier     "Layout0"

    Screen      0   "ScreenNvidia0" 0 0
    Screen      1   "ScreenNvidia1"  RightOf "ScreenNvidia0"
    Screen      2   "ScreenIntel"    RightOf "ScreenNvidia1"

    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "true"
EndSection

Section "Files"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "MonitorNvidia0"
    VendorName     "Unknown"
    ModelName      "Samsung SyncMaster"
    HorizSync       30.0 - 81.0
    VertRefresh     50.0 - 63.0
    Option         "DPMS"
EndSection
Section "Monitor"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "MonitorNvidia1"
    VendorName     "Unknown"
    ModelName      "Samsung SyncMaster"
    HorizSync       30.0 - 81.0
    VertRefresh     50.0 - 63.0
    Option         "DPMS"
EndSection

Section "Monitor"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "MonitorIntel"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       30.0 - 81.0
    VertRefresh     50.0 - 63.0
    Option         "DPMS"
EndSection
Section "Device"
    Identifier     "DeviceNvidia0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BusID          "1:0:0"
    Option         "RegistryDwords" "EnableBrightnessControl=1"
    Screen         0
EndSection
Section "Device"
    Identifier     "DeviceNvidia1"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BusID          "1:0:0"
    Option         "RegistryDwords" "EnableBrightnessControl=1"
    Screen         1
EndSection

Section "Device"
    Identifier     "DeviceIntel"
    Driver         "intel"
    BusID          "0:2:0"

       Option          "monitor-VGA1"  "VGA1"
    Option          "monitor-TV"   "TV"
    Option          "monitor-LVCD1" "LVCD1"
Option "Clone" "off"
EndSection

Section "Monitor"
    Identifier      "VGA1"
EndSection

Section "Monitor"
    Identifier      "LVCD1"
    Option          "DPMS"
EndSection

Section "Monitor"
    Identifier      "TV"
    Option  "Ignore" "false"
EndSection

Section "Screen"
    Identifier  "ScreenNvidia0"
    Device      "DeviceNvidia0"
    Monitor     "MonitorNvidia0"
    DefaultDepth 24
    SubSection "Display"
    Depth 24
    Modes "1920x1200"
    EndSubSection
EndSection

Section "Screen"
    Identifier  "ScreenNvidia1"
    Device      "DeviceNvidia1"
    Monitor     "MonitorNvidia1"
    DefaultDepth 24
    SubSection "Display"
    Depth 24
    Modes "1920x1200"
    EndSubSection
EndSection

Section "Screen"
    Identifier     "ScreenIntel"
    Device         "DeviceIntel"
    Monitor        "MonitorIntel"
    DefaultDepth 24
    SubSection "Display"
    Depth 24
    Modes "1900x1200"
    EndSubSection
    SubSection "Display"
    Depth 24
    Modes "1920x1200"
    EndSubSection

EndSection

In the "DeviceIntel" section is my last attempt to get more than one monitor on the Intel card.

Here is an extract of my "lspci":

$ lspci |grep VGA
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
01:00.0 VGA compatible controller: nVidia Corporation Device 1057 (rev a1)

If you don't use the NVidia card you will only be able to use the single VGA port on your notebook. Even if you connect to a docking station both, dvi and display ports won't be available unless you use the NVidia card.