我有 ubuntu 14.04 和 nvidia 驱动程序 331.38。我的笔记本有 GeForce GT 555M 和 Intel 显卡。ubuntu 运行正常，除了一个问题。我想连接两个外接显示器，但发现 nvidia-settings 甚至检测不到笔记本内置显示器。如果我连接 HDMI 和 VGA，nvidia-settings 只会显示 VGA 显示器。
如果没有连接外部显示器，则 nvidia-xconfig 的输出为：
nvidia-xconfig --query-gpu-info
Number of GPUs: 1
GPU #0:
Name : GeForce GT 555M
UUID : GPU-6bb6fcda-c642-b2ee-4040-3c4024d7f7a7
PCI BusID : PCI:1:0:0
Number of Display Devices: 0
如果连接了两个外部显示器，则 nvidia-xconfig 的输出：
nvidia-xconfig --query-gpu-info
Number of GPUs: 1
GPU #0:
Name : GeForce GT 555M
UUID : GPU-6bb6fcda-c642-b2ee-4040-3c4024d7f7a7
PCI BusID : PCI:1:0:0
Number of Display Devices: 1
Display Device 0 (DFP-0):
EDID Name : Samsung SyncMaster
Minimum HorizSync : 30.000 kHz
Maximum HorizSync : 81.000 kHz
Minimum VertRefresh : 56 Hz
Maximum VertRefresh : 75 Hz
Maximum PixelClock : 140.000 MHz
Maximum Width : 1280 pixels
Maximum Height : 1024 pixels
Preferred Width : 1280 pixels
Preferred Height : 1024 pixels
Preferred VertRefresh : 60 Hz
Physical Width : 380 mm
Physical Height : 300 mm
xrandr 的输出：
Screen 0: minimum 8 x 8, current 1280 x 1024, maximum 16384 x 16384
HDMI-0 connected primary 1280x1024+0+0 (normal left inverted right x axis y axis) 380mm x 300mm
1280x1024 60.0 + 75.0*
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
LVDS-1-0 connected 1280x1024+0+0 344mm x 194mm
1920x1080 60.0 + 59.9
1680x1050 60.0 59.9
1600x1024 60.2
1400x1050 60.0
1280x1024 60.0*
1440x900 59.9
1280x960 60.0
1360x768 59.8 60.0
1152x864 60.0
1024x768 60.0 60.0
960x720 60.0
928x696 60.1
896x672 60.0
960x600 60.0
960x540 60.0
800x600 60.0 60.3 56.2
840x525 60.0 59.9
800x512 60.2
700x525 60.0
640x512 60.0
720x450 59.9
640x480 60.0 59.9
680x384 59.8 60.0
576x432 60.1
512x384 60.0
400x300 60.3 56.3
320x240 60.1
VGA-1-0 connected 1280x1024+0+0 376mm x 301mm
1280x1024 60.0 + 75.0*
1280x960 60.0
1152x864 75.0
1024x768 75.1 70.1 60.0
832x624 74.6
800x600 72.2 75.0 60.3 56.2
640x480 75.0 72.8 66.7 60.0
720x400 70.1
1280x1024 (0x4a) 108.0MHz
h: width 1280 start 1328 end 1440 total 1688 skew 0 clock 64.0KHz
v: height 1024 start 1025 end 1028 total 1066 clock 60.0Hz
1280x960 (0x4c) 108.0MHz
h: width 1280 start 1376 end 1488 total 1800 skew 0 clock 60.0KHz
v: height 960 start 961 end 964 total 1000 clock 60.0Hz
1024x768 (0x51) 65.0MHz
h: width 1024 start 1048 end 1184 total 1344 skew 0 clock 48.4KHz
v: height 768 start 771 end 777 total 806 clock 60.0Hz
800x600 (0x58) 40.0MHz
h: width 800 start 840 end 968 total 1056 skew 0 clock 37.9KHz
v: height 600 start 601 end 605 total 628 clock 60.3Hz
800x600 (0x59) 36.0MHz
h: width 800 start 824 end 896 total 1024 skew 0 clock 35.2KHz
v: height 600 start 601 end 603 total 625 clock 56.2Hz
640x480 (0x61) 25.2MHz
h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
v: height 480 start 490 end 492 total 525 clock 59.9Hz
1280x1024 (0x2e9) 135.0MHz
h: width 1280 start 1296 end 1440 total 1688 skew 0 clock 80.0KHz
v: height 1024 start 1025 end 1028 total 1066 clock 75.0Hz
1152x864 (0x2ea) 108.0MHz
h: width 1152 start 1216 end 1344 total 1600 skew 0 clock 67.5KHz
v: height 864 start 865 end 868 total 900 clock 75.0Hz
1024x768 (0x2ec) 75.0MHz
h: width 1024 start 1048 end 1184 total 1328 skew 0 clock 56.5KHz
v: height 768 start 771 end 777 total 806 clock 70.1Hz
800x600 (0x2ee) 50.0MHz
h: width 800 start 856 end 976 total 1040 skew 0 clock 48.1KHz
v: height 600 start 637 end 643 total 666 clock 72.2Hz
800x600 (0x2ed) 49.5MHz
h: width 800 start 816 end 896 total 1056 skew 0 clock 46.9KHz
v: height 600 start 601 end 604 total 625 clock 75.0Hz
640x480 (0x2ef) 31.5MHz
h: width 640 start 656 end 720 total 840 skew 0 clock 37.5KHz
v: height 480 start 481 end 484 total 500 clock 75.0Hz
配置xorg.conf
# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 331.20 (buildd@roseapple) Mon Feb 3 15:07:22 UTC 2014
# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 331.38 (buildmeister@swio-display-x64-rhel04-15) Wed Jan 8 19:53:14 PST 2014
Section "ServerLayout"
Identifier "Layout0"
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
Option "Xinerama" "0"
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"
Identifier "Monitor0"
VendorName "Unknown"
ModelName "Samsung SyncMaster"
HorizSync 30.0 - 81.0
VertRefresh 56.0 - 75.0
Option "DPMS"
EndSection
Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce GT 555M"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "Stereo" "0"
Option "nvidiaXineramaInfoOrder" "DFP-0"
Option "metamodes" "1280x1024_75 +0+0"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
SubSection "Display"
Depth 24
EndSubSection
EndSection
非常感谢您的帮助！