[求助]关于双头显示，基本解决，还有点问题，大家帮看看

dnastar

新买了一个宽屏显示 器, 最佳分辨率是1440＊900，笔记本上是1024＊768，
无论我在SAX2里怎么设置，外接的显示器都是以克隆的方式显示1024＊768，不知有什么办法才到弄到我想要的下列结果啊：
1。内置显示为1024＊768， 外接1440＊900，扩展显示或者克隆显示
2。关掉内显示之后用1440＊900输出到外接显示上也可以接受啊。

主要问题可能是我的显示太差，是ATI M7500，只能用系统自带的驱动。

多谢！

windrose

http://gentoo-wiki.com/HOWTO_Dual_Monitors

dnastar

Post by windrose;1819507
http://gentoo-wiki.com/HOWTO_Dual_Monitors

多谢！！
按照上面给的例已经基本搞定了，现在有个问题，就是觉得外接的显示器好象是从4:3压成了16／9，看起来有些扁。以后慢慢调吧。

dnastar

我把现在的设置帖出来，大家看看是哪个地方需要改动,感觉主要还是两个屏的显示都是4：3，才弄成这样的：


Section "Device"
Identifier "ATI Technologies, Inc. Radeon Mobility 7500 (M7 LW)"
Driver  "radeon"
BusID  "CI:1:0:0"
Option  "DynamicClocks" "on"
## Option  "backingstore" "on"
# The next line would enables Fn-F7/Fn-F8 to switch display outputs/screen
# resizing, if I had a newer version of the 'radeon' driver.
## Option  "BIOSHotkeys" "on"
# Surprise -- it seems that MergedFB is on by the default nowadays?  And if
# I don't explicitly list any MetaModes, then I can't use xrandr at all?
# Unfortunately, disabling MergedFB causes a side effect: if I then plug in
# an external monitor, the picture is shifted and wavy.  Unusable.
## Option  "MergedFB" "false"

# It won't give me the chance to get a  1440x900 on my external display without
# this
Option  "CRT2HSync" "30-83"
Option  "CRT2VRefresh" "56-76"
# and this
   Option  "MetaModes" "1024x768 800x600 640x480 1024x768+ 1440x900"

# https://help.ubuntu.com/community/CompositeManager/AIGLXOnEdgy: for AIGLX
# I need
    Option  "XAANoOffscreenPixmaps" "true"
EndSection

Section "Device"
Identifier "MergedFB ATI Technologies, Inc. Radeon Mobility 7500 (M7 LW)"
Driver  "radeon"
BusID  "CI:1:0:0"
Option  "DynamicClocks" "on"
Option  "MergedFB" "true"
Option  "CRT2Position" "LeftOf"
    # This allows X to use MergedFB if the external monitor is not connected
    # when I start X.  The ranges are taken from DDC values of the CTX monitor
    # I use at the office; as listed in Xorg.log.
Option  "CRT2HSync" "30-81"
Option  "CRT2VRefresh" "56-76"
    # The next line lets me switch between dual-head and several clone modes
    # of varying resolutions with xrandr.
Option  "MetaModes" "1024x768-1024x768 1024x768 800x600 640x480"
    # My laptop's internal LCD is 100dpi.  The external LCD is designed
    # for  1440x900, and the picture is streched.  The radeon driver computes
    # its DPI by looking at the physical size of the external LCD, and gets
    # ~65 DPI.  I want to override that.
Option  "MergedDPI" "100 100"
    # This should speed up RENDER acceleration and perhaps make compositing not
    # so terribly slow.  What it does, is make EVERYTHING slow.
    # Maybe it is time to try again?
## Option  "AccelMethod" "EXA"

        Option  "XAANoOffscreenPixmaps" "true"
EndSection

Section "Device"
Identifier "MergedFB2 ATI Technologies, Inc. Radeon Mobility 7500 (M7 LW)"
Driver  "radeon"
BusID  "CI:1:0:0"
Option  "DynamicClocks" "on"
Option  "MergedFB" "true"
Option  "CRT2Position" "LeftOf"
    # This allows X to use MergedFB if the external monitor is not connected
    # when I start X.  The ranges are taken from DDC values of the CTX monitor
    # I use at the office; as listed in Xorg.log.
Option  "CRT2HSync" "30-81"
Option  "CRT2VRefresh" "56-76"
    # The next line lets me switch between dual-head and several clone modes
    # of varying resolutions with xrandr.
Option  "MetaModes" "1024x768-1440x900  1024x768-1024x768 1024x768+ 1440x900  1440x900 1024x768 800x600 640x480"
    # A newer version of the radeon driver has an option that disables vertical
    # scrolling for the 1024x768 part.
Option  "MergedNonRectangular" "true"
    # In 1024x768- 1440x900  mode the DPI is correct (100), but in all other
    # modes it is weird.  Try to override
Option  "MergedDPI" "100 100"
# https://help.ubuntu.com/community/CompositeManager/AIGLXOnEdgy: for AIGLX
# I need
   Option  "XAANoOffscreenPixmaps" "true"
# but then I wonder if AIGLX + MergedFB is a good idea.  The 3D engine is
# limited to 2048x2048, which is less than my MergedFB desktop.

    # This should speed up RENDER acceleration and perhaps make compositing not
    # so terribly slow.  What it does, is make EVERYTHING slow.
    # Maybe it is time to try again?  Well, it is still painfully slow, without
    # a composition manager.  Manageable with a composition manager.  compiz
    # fails to work, though:
    #   libGL warning: 3D driver claims to not support visual 0x4b
    #   compiz.real: GLX_EXT_texture_from_pixmap is missing
    #   compiz.real: Failed to manage screen: 0
    #   compiz.real: No manageable screens found on display :0.0
    # why? glxinfo reports I have dri, and I have GLX_EXT_texture_from_pixmap.
## Option  "AccelMethod" "EXA"
EndSection

Section "Device"
Identifier "Screen0 ATI Technologies, Inc. Radeon Mobility 7500 (M7 LW)"
Driver  "radeon"
BusID  "CI:1:0:0"
Option  "DynamicClocks" "on"
Screen  0
EndSection

Section "Device"
Identifier "Screen1 ATI Technologies, Inc. Radeon Mobility 7500 (M7 LW)"
Driver  "radeon"
BusID  "CI:1:0:0"
Option  "DynamicClocks" "on"
Screen  1
EndSection

Section "Monitor"
Identifier "Generic Monitor"
Option  "DPMS"
EndSection

Section "Monitor"
Identifier "Second Monitor"
Option  "DPMS"
EndSection

Section "Screen"
Identifier "Default Screen"
Device  "ATI Technologies, Inc. Radeon Mobility 7500 (M7 LW)"
Monitor  "Generic Monitor"
DefaultDepth 24
SubSection "Display"
  Depth  16
  Modes  "1024x768" "800x600" "640x480" " 1440x900"
EndSubSection
SubSection "Display"
  Depth  24
  Modes  "1024x768" "800x600" "640x480" " 1440x900"
EndSubSection
EndSection

Section "Screen"
Identifier "MergedFB Screen"
Device  "MergedFB ATI Technologies, Inc. Radeon Mobility 7500 (M7 LW)"
Monitor  "Generic Monitor"
DefaultDepth 24
SubSection "Display"
  Depth  1
  Modes  "1024x768"
EndSubSection
SubSection "Display"
  Depth  4
  Modes  "1024x768"
EndSubSection
SubSection "Display"
  Depth  8
  Modes  "1024x768"
EndSubSection
SubSection "Display"
  Depth  15
  Modes  "1024x768"
EndSubSection
SubSection "Display"
  Depth  16
  Modes  "1024x768"
EndSubSection
SubSection "Display"
  Depth  24
  Modes  "1024x768"
EndSubSection
EndSection

Section "Screen"
Identifier "MergedFB2 Screen"
Device  "MergedFB2 ATI Technologies, Inc. Radeon Mobility 7500 (M7 LW)"
Monitor  "Generic Monitor"
DefaultDepth 24
## DefaultDepth 16
SubSection "Display"
  Depth  24
  Modes  " 1440x900" "1024x768"
EndSubSection
        # People keep saying add this for compiz.  I want to know what it does.
        Option "AddARGBGLXVisuals" "true"
EndSection

Section "Screen"
Identifier "Screen0"
Device  "Screen0 ATI Technologies, Inc. Radeon Mobility 7500 (M7 LW)"
Monitor  "Generic Monitor"
DefaultDepth 24
SubSection "Display"
  Depth  1
  Modes  "1024x768"
EndSubSection
SubSection "Display"
  Depth  4
  Modes  "1024x768"
EndSubSection
SubSection "Display"
  Depth  8
  Modes  "1024x768"
EndSubSection
SubSection "Display"
  Depth  15
  Modes  "1024x768"
EndSubSection
SubSection "Display"
  Depth  16
  Modes  "1024x768"
EndSubSection
SubSection "Display"
  Depth  24
  Modes  "1024x768"
EndSubSection
EndSection

Section "Screen"
Identifier "Screen1"
Device  "Screen1 ATI Technologies, Inc. Radeon Mobility 7500 (M7 LW)"
Monitor  "Second Monitor"
DefaultDepth 24
SubSection "Display"
  Depth  1
  Modes  " 1440x900" "1024x768"
EndSubSection
SubSection "Display"
  Depth  4
  Modes  " 1440x900" "1024x768"
EndSubSection
SubSection "Display"
  Depth  8
  Modes  " 1440x900" "1024x768"
EndSubSection
SubSection "Display"
  Depth  15
  Modes  " 1440x900" "1024x768"
EndSubSection
SubSection "Display"
  Depth  16
  Modes  " 1440x900" "1024x768"
EndSubSection
SubSection "Display"
  Depth  24
  Modes  " 1440x900" "1024x768"
EndSubSection
EndSection

Section "ServerLayout"
Identifier "DefaultLayout"
Screen  "Default Screen"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
EndSection

Section "ServerLayout"
Identifier "AiglxLayout"
Screen  "Default Screen"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
# https://help.ubuntu.com/community/CompositeManager/AIGLXOnEdgy
# Hm, but isn't it enabled by default?  My xorg.0.log mentions it anyway
Option  "AIGLX"  "true"
EndSection


Section "ServerLayout"
Identifier "MergedFBLayout"
Screen  "MergedFB Screen"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
EndSection

Section "ServerLayout"
Identifier "MergedFB2Layout"
Screen  "MergedFB2 Screen"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
EndSection

Section "ServerLayout"
Identifier "XineramaLayout"
Screen  "Screen0"
Screen  "Screen1" LeftOf "Screen0"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
Option  "Xinerama" "true"
EndSection

Section "ServerLayout"
Identifier "TwoHeadLayout"
Screen  "Screen0"
Screen  "Screen1" LeftOf "Screen0"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
EndSection

Section "DRI"
Mode 0666
EndSection

Section "ServerFlags"
# MergedFB2: best for dual-head, but no compiz
Option  "DefaultServerLayout" "MergedFB2Layout"
Option  "AllowMouseOpenFail" "on"
EndSection