我有一个（令人高兴的）不幸，我有 3 个显卡。它们是 XFX Radeon 5750s。每个都通过 dvi 驱动 2 个显示器。我在 Fedora 15（gnome 3）上运行它们时遇到了很多困难。所以我的设置是 3 列 2 个显示器（每列上部的显示器倒置安装，以减少显示器之间的边框）。
当出现（图形）登录屏幕时，所有 6 个都有蓝色条纹背景，这一定是默认设置，但是当我登录时，事情变得有趣。
在下面的 xorg.conf 中，您将只看到服务器布局中的 2 个屏幕，而其他 4 个屏幕已被注释掉。仅使用 2 个屏幕登录时效果很好（它甚至记得顶部的屏幕是倒置的，应该被视为位于下方的屏幕之上，我不确定它将此信息存储在哪里，但我使用图形“显示”设置进行设置）
但是，只要我取消注释第三个或更多屏幕，登录时就会出现错误消息。这是一条友好但帮助不大的消息（哦不！出了点问题。出现问题，系统无法恢复。请注销并重试）。
如果我不使用 xorg.conf，则“显示”首选项窗格仅显示我的一张显卡上的两个显示器
感谢所有能帮助我的人！（xorg.conf，然后是下面的 lspci，以及 xorg log）
xorg配置文件
Section "ServerLayout"
Identifier "X.org Configured"
Screen "Screen0" 0 0
Screen "Screen1" Below "Screen0"
# Screen "Screen2" RightOf "Screen0"
# Screen "Screen3" RightOf "Screen1"
# Screen "Screen4" RightOf "Screen3"
# Screen "Screen5" RightOf "Screen4"
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
EndSection
Section "Files"
ModulePath "/usr/lib/xorg/modules"
FontPath "catalogue:/etc/X11/fontpath.d"
FontPath "built-ins"
EndSection
Section "Module"
Load "record"
Load "dri"
Load "dbe"
Load "extmod"
Load "dri2"
Load "glx"
EndSection
Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
EndSection
Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/input/mice"
Option "ZAxisMapping" "4 5 6 7"
EndSection
Section "Monitor"
Identifier "Monitor0"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
EndSection
Section "Monitor"
Identifier "Monitor1"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
EndSection
Section "Monitor"
Identifier "Monitor2"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
EndSection
Section "Monitor"
Identifier "Monitor3"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
EndSection
Section "Monitor"
Identifier "Monitor4"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
EndSection
Section "Monitor"
Identifier "Monitor5"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
EndSection
Section "Device"
Identifier "Card0"
Driver "radeon"
BusID "PCI:4:0:0"
EndSection
Section "Device"
Identifier "Card1"
Driver "radeon"
BusID "PCI:5:0:0"
EndSection
Section "Device"
Identifier "Card2"
Driver "radeon"
BusID "PCI:6:0:0"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection
Section "Screen"
Identifier "Screen1"
Device "Card0"
Monitor "Monitor1"
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection
Section "Screen"
Identifier "Screen2"
Device "Card1"
Monitor "Monitor2"
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection
Section "Screen"
Identifier "Screen3"
Device "Card1"
Monitor "Monitor3"
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection
Section "Screen"
Identifier "Screen4"
Device "Card2"
Monitor "Monitor4"
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection
Section "Screen"
Identifier "Screen5"
Device "Card2"
Monitor "Monitor5"
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection
lspci 输出如下
[tgm@tgm ~]$ lspci
00:00.0 Host bridge: Intel Corporation 5520/5500/X58 I/O Hub to ESI Port (rev 13)
00:01.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 1 (rev 13)
00:03.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 3 (rev 13)
00:07.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 7 (rev 13)
00:14.0 PIC: Intel Corporation 5520/5500/X58 I/O Hub System Management Registers (rev 13)
00:14.1 PIC: Intel Corporation 5520/5500/X58 I/O Hub GPIO and Scratch Pad Registers (rev 13)
00:14.2 PIC: Intel Corporation 5520/5500/X58 I/O Hub Control Status and RAS Registers (rev 13)
00:14.3 PIC: Intel Corporation 5520/5500/X58 I/O Hub Throttle Registers (rev 13)
00:1a.0 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #4
00:1a.1 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #5
00:1a.2 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #6
00:1a.7 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB2 EHCI Controller #2
00:1b.0 Audio device: Intel Corporation 82801JI (ICH10 Family) HD Audio Controller
00:1c.0 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 1
00:1c.1 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Port 2
00:1c.2 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 3
00:1d.0 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #1
00:1d.1 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #2
00:1d.2 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #3
00:1d.7 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB2 EHCI Controller #1
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 90)
00:1f.0 ISA bridge: Intel Corporation 82801JIR (ICH10R) LPC Interface Controller
00:1f.2 IDE interface: Intel Corporation 82801JI (ICH10 Family) 4 port SATA IDE Controller #1
00:1f.3 SMBus: Intel Corporation 82801JI (ICH10 Family) SMBus Controller
00:1f.5 IDE interface: Intel Corporation 82801JI (ICH10 Family) 2 port SATA IDE Controller #2
02:00.0 PCI bridge: nVidia Corporation NF200 PCIe 2.0 switch for mainboards (rev a3)
03:00.0 PCI bridge: nVidia Corporation NF200 PCIe 2.0 switch for mainboards (rev a3)
03:02.0 PCI bridge: nVidia Corporation NF200 PCIe 2.0 switch for mainboards (rev a3)
04:00.0 VGA compatible controller: ATI Technologies Inc Juniper [Radeon HD 5750 Series]
04:00.1 Audio device: ATI Technologies Inc Juniper HDMI Audio [Radeon HD 5700 Series]
05:00.0 VGA compatible controller: ATI Technologies Inc Juniper [Radeon HD 5750 Series]
05:00.1 Audio device: ATI Technologies Inc Juniper HDMI Audio [Radeon HD 5700 Series]
06:00.0 VGA compatible controller: ATI Technologies Inc Juniper [Radeon HD 5750 Series]
06:00.1 Audio device: ATI Technologies Inc Juniper HDMI Audio [Radeon HD 5700 Series]
07:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 02)
08:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 02)
xorg 日志（由于太长所以发布到 fpaste。感谢 marcusw 的请求）
xorg 日志在 xorg.conf 中启用了所有 6 个监视器（它们全部打开并显示蓝色，但是其中一个会收到前面提到的用户友好的错误消息）。 http://www.fpaste.org/X63H/
答案1
那么登录管理器屏幕工作正常吗？
尝试不同的桌面环境。那些不太现代的桌面环境（如 icewm）也许可以。
运行时xrandr将显示最大可能的屏幕尺寸（我的是 8192x8192）。您的 DE 是否尝试设置更大的屏幕尺寸？
您可以尝试在 xorg.conf 中指定屏幕尺寸，因此您可以尝试一些较小的尺寸（例如 800x600）并进行测试。但由于登录管理器可以正常工作，因此这可能无法解决问题。
另外，检查 $HOME/.xsession-errors 文件。
您还可以尝试停止登录管理器，通过 ssh 连接到机器，启动 X（不带登录管理器），然后手动启动桌面环境并尝试查看它是否给出任何错误消息。