最新更新：
终于弄好了，双屏显示，左右各一个屏。
但由于驱动最大只支持2048x2048的虚拟屏幕，所以本本的分辨率被迫下调
今天突然想试试，于是借同学显示器摆弄了一下午
关于双头显示，主要有三种：clone，独立桌面，桌面扩展
clone：很好办，基本上xrandr --auto就能搞定
独立桌面：有点不明白，网上有人说搞定了，但打开的对话框无法在两个桌面之间移动。我是没弄出来，不知道鼠标能不能自由移动
桌面扩展：成功运行，但有问题。下面再说
不管是上面哪一种模式，有一个问题，就是分辨率的问题
我本本是1280x800，借来的显示器是1280x1024。
无论我怎么设置：在xorg.conf的Monitor和Screen中设置，或用xrandr设置size，两种办法都不行。出现的问题总是：
桌面超出了本本的显示范围（上下突出去了），而外接显示器则压缩了桌面（显示器上下都留出来了一截，且明显被压缩）
下面是我的xorg.conf，双头显示的部分已经被我注释，大家看看有什么问题：
请把注意力集中在分辨率上
代码： 全选
Section "Module"
Load "dbe"
# Load "type1"
# Load "freetype"
# Load "xtt"
Load "ddc"
Load "glx"
Load "dri"
# Load "dri2"
Load "record"
Load "int10"
Load "bitmap"
Load "extmod"
Load "i2c"
Load "synaptics"
EndSection
Section "ServerFlags"
Option "DefaultServerLayout" "default Layout"
# Option "NoTrapSignals"
# Option "DontVTSwitch" "true"
# Option "DontZap" "true"
# Option "DontZoom" "true"
# Option "DisableVidModeExtension" "true"
# Option "AllowNonLocalXvidtune"
# Option "DisableModInDev"
# Option "AllowNonLocalModInDev"
Option "AutoAddDevice" "false"
# Option "AIGLX" "true"
# Option "Xinerama" "true"
EndSection
Section "Files"
FontPath "/usr/share/fonts/misc"
FontPath "/usr/share/fonts/100dpi:unscaled"
FontPath "/usr/share/fonts/75dpi:unscaled"
#FontPath "/usr/share/fonts/TTF"
#FontPath "/usr/share/fonts/Type1"
#FontPath "/usr/lib/X11/fonts/local/"
#FontPath "/usr/lib/X11/fonts/misc/"
#FontPath "/usr/lib/X11/fonts/75dpi/:unscaled"
#FontPath "/usr/lib/X11/fonts/100dpi/:unscaled"
#FontPath "/usr/lib/X11/fonts/Type1/"
#FontPath "/usr/lib/X11/fonts/TrueType/"
#FontPath "/usr/lib/X11/fonts/freefont/"
#FontPath "/usr/lib/X11/fonts/75dpi/"
#FontPath "/usr/lib/X11/fonts/100dpi/"
#ModulePath "/usr/lib/modules"
EndSection
Section "InputDevice"
Identifier "Laptop Keyboard"
Driver "kbd"
Option "Device" "/dev/input/event1"
Option "Protocol" "Standard"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "acer_laptop"
Option "XkbLayout" "us"
EndSection
Section "InputDevice"
Identifier "Laptop Touchpad"
Driver "synaptics"
Option "AlwaysCore" "true"
Option "Device" "/dev/psaux"
Option "Protocol" "auto-dev"
Option "Emulate3Buttons" "true"
Option "ZAxisMapping" "4 5 6 7"
Option "TapButton1" "1"
Option "TapButton2" "3"
Option "CornerCoasting" "true"
Option "VertEdgeScroll" "true"
Option "HorizEdgeScroll" "true"
Option "VertTwoFingerScroll" "true"
Option "HorizTwoFingerScroll" "true"
Option "UpDownScrolling" "true"
Option "LeftRightScrolling" "true"
# Option "LockedDrags" "true"
EndSection
Section "Device"
Identifier "Laptop GPU"
Driver "intel"
BusID "PCI:0:2:0"
# Option "LVDS" "Laptop Monitor"
# Option "VGA" "Second Monitor"
# Option "DRI" "true"
Option "AccelMethod" "EXA"
Option "Tiling" "false"
# Option "MigrationHeuristic" "greedy"
# Option "ExaNoComposite" "false"
EndSection
#
#Section "Device"
# Identifier "Second GPU"
# Driver "intel"
# BusID "PCI:0:2:1"
## Option "DRI" "false"
#EndSection
#
Section "Monitor"
Identifier "Laptop Monitor"
Option "DPMS"
# Option "Enable" "true"
DisplaySize 336 210 # 96 DPI @ 1280x800
HorizSync 28-64
VertRefresh 60
EndSection
#
#Section "Monitor"
# Identifier "Second Monitor"
# Option "DPMS"
## Option "Ignore" "true"
# Option "LeftOf" "Laptop Monitor"
## # DisplaySize 168 126 # 96 DPI @ 640x480
## # # DisplaySize 210 157 # 96 DPI @ 800x600
## # # DisplaySize 269 201 # 96 DPI @ 1024x768
## # # DisplaySize 302 227 # 96 DPI @ 1152x864
## # # DisplaySize 336 252 # 96 DPI @ 1280x960
## # # DisplaySize 336 210 # 96 DPI @ 1280x800 (non 4:3 aspect)
# DisplaySize 339 271 # 96 DPI @ 1280x1024 (non 4:3 aspect)
## # # DisplaySize 370 277 # 96 DPI @ 1400x1050
## # # DisplaySize 380 238 # 96 DPI @ 1440x900 (non 4:3 aspect)
## # # DisplaySize 420 315 # 96 DPI @ 1600x1200
## # # DisplaySize 444 277 # 96 DPI @ 1680x1050 (non 4:3 aspect)
## # # DisplaySize 506 315 # 96 DPI @ 1920x1200 (non 4:3 aspect)
## #
# HorizSync 28-64
# VertRefresh 60
#EndSection
#
Section "Screen"
Identifier "Laptop Screen"
Monitor "Laptop Monitor"
Device "Laptop GPU"
DefaultDepth 24
# SubSection "Display"
# Depth 8
# Modes "1280x800" "800x600"
# ViewPort 0 0
# EndSubSection
# SubSection "Display"
# Depth 16
# Modes "1280x800" "800x600"
# ViewPort 0 0
# EndSubSection
SubSection "Display"
Depth 24
Modes "1280x800" "800x600"
# Virtual 2560 1824
EndSubSection
EndSection
#
#Section "Screen"
# Identifier "Second Screen"
# Monitor "Second Monitor"
# Device "Second GPU"
# DefaultDepth 24
# SubSection "Display"
# Depth 24
# Modes "1280x1024"
## viewPort 0 1
# EndSubSection
#EndSection
#
Section "ServerLayout"
Identifier "Default Layout"
Screen "Laptop Screen"
# Screen 0 "Laptop Screen" 0 0
# Screen 1 "Second Screen" RightOf "Laptop Screen"
InputDevice "Laptop Touchpad" "CorePointer"
InputDevice "Laptop Keyboard" "CoreKeyboard"
EndSection
Section "Extensions"
Option "Composite" "True"
EndSection
Section "DRI"
Mode 0666
EndSection
