我正在尝试配置几个 Ubuntu 14.04 桌面工作站，每个工作站总共有 4 个显示器。我想将它们配置为有 2 个独立屏幕，每个屏幕在两个显示器上镜像显示。
我目前拥有 4 台显示器，它们都以正确的分辨率镜像相同的输出。
我尝试使用xrandr来将我的两个显示器相对于其他显示器定位，并进行--same-as镜像，如下所示：
xrandr --output DisplayPort-0 --primary
xrandr --output DisplayPort-1 --same-as DisplayPort-0
xrandr --output DisplayPort-1-2 --right-of DisplayPort-0
xrandr --output DisplayPort-1-3 --same-as DisplayPort-1-2
当我尝试运行包含这些命令的脚本时，两个显示器（xrandr 称为 DisplayPort-1-2 和 DisplayPort-1-3）会冻结在当前显示的图像上，并且不再更新。奇怪的是，如果我使用 arandr 以图形方式查看配置，显示器的布局与我预期的完全一致。但我并不期望如此xrandr，所以我可能在这里做了一些愚蠢的事情。
如果这很重要的话，我会使用 radeon 驱动程序和 Xfce。在尝试手动使用之前，我尝试过使用 Unity 和 Xfce 中的显示设置菜单xrandr，但使用它们的效果更差。
的输出sudo lshw -c video为：
*-display
description: VGA compatible controller
product: RV620 GL [FirePro 2260]
vendor: Advanced Micro Devices, Inc. [AMD/ATI]
physical id: 0
bus info: pci@0000:03:00.0
version: 00
width: 64 bits
clock: 33MHz
capabilities: pm pciexpress msi vga_controller bus_master cap_list rom
configuration: driver=radeon latency=0
resources: irq:109 memory:d0000000-dfffffff memory:f7df0000-f7dfffff ioport:dc00(size=256) memory:f7e00000-f7e1ffff
*-display
description: VGA compatible controller
product: RV620 GL [FirePro 2260]
vendor: Advanced Micro Devices, Inc. [AMD/ATI]
physical id: 0
bus info: pci@0000:04:00.0
version: 00
width: 64 bits
clock: 33MHz
capabilities: pm pciexpress msi vga_controller bus_master cap_list rom
configuration: driver=radeon latency=0
resources: irq:110 memory:e0000000-efffffff memory:f7bf0000-f7bfffff io
xrandr（运行上面显示的命令之后）的输出是：
Screen 0: minimum 320 x 200, current 3840 x 1200, maximum 8192 x 8192
DisplayPort-0 connected primary 1920x1200+0+0 (normal left inverted right x axis y axis) 518mm x 324mm
1920x1200 60.0*+
1600x1200 60.0
1280x1024 75.0 60.0
1152x864 75.0
1024x768 75.1 60.0
800x600 75.0 60.3
640x480 75.0 60.0
720x400 70.1
DisplayPort-1 connected 1920x1200+0+0 (normal left inverted right x axis y axis) 518mm x 324mm
1920x1200 60.0*+
1920x1080 60.0 50.0 59.9 24.0 24.0
1920x1080i 60.1 50.0 60.0
1600x1200 60.0
1280x1024 75.0 60.0
1152x864 75.0
1280x720 60.0 50.0 59.9
1440x576i 50.1
1024x768 75.1 60.0
1440x480i 60.1 60.1
800x600 75.0 60.3
720x576 50.0
720x480 60.0 59.9
640x480 75.0 60.0 59.9
720x400 70.1
DisplayPort-1-2 connected 1920x1200+1920+0 518mm x 324mm
1920x1200 60.0*+
1920x1080 60.0 50.0 59.9 24.0 24.0
1920x1080i 60.1 50.0 60.0
1600x1200 60.0
1280x1024 75.0 60.0
1152x864 75.0
1280x720 60.0 50.0 59.9
1440x576i 50.1
1024x768 75.1 60.0
1440x480i 60.1 60.1
800x600 75.0 60.3
720x576 50.0
720x480 60.0 59.9
640x480 75.0 60.0 59.9
720x400 70.1
DisplayPort-1-3 connected 1920x1200+1920+0 518mm x 324mm
1920x1200 60.0*+
1600x1200 60.0
1280x1024 75.0 60.0
1152x864 75.0
1024x768 75.1 60.0
800x600 75.0 60.3
640x480 75.0 60.0
720x400 70.1
1920x1200 (0x44) 154.0MHz
h: width 1920 start 1968 end 2000 total 2080 skew 0 clock 74.0KHz
v: height 1200 start 1203 end 1209 total 1235 clock 60.0Hz
1920x1080 (0x45) 148.5MHz
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 67.5KHz
v: height 1080 start 1084 end 1089 total 1125 clock 60.0Hz
1920x1080 (0x46) 148.5MHz
h: width 1920 start 2448 end 2492 total 2640 skew 0 clock 56.2KHz
v: height 1080 start 1084 end 1089 total 1125 clock 50.0Hz
1920x1080 (0x47) 148.4MHz
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 67.4KHz
v: height 1080 start 1084 end 1089 total 1125 clock 59.9Hz
1920x1080i (0x48) 74.2MHz
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 33.8KHz
v: height 1080 start 1084 end 1094 total 1125 clock 60.1Hz
1920x1080i (0x49) 74.2MHz
h: width 1920 start 2448 end 2492 total 2640 skew 0 clock 28.1KHz
v: height 1080 start 1084 end 1094 total 1125 clock 50.0Hz
1920x1080 (0x4a) 74.2MHz
h: width 1920 start 2558 end 2602 total 2750 skew 0 clock 27.0KHz
v: height 1080 start 1084 end 1089 total 1125 clock 24.0Hz
1920x1080i (0x4b) 74.2MHz
h: width 1920 start 2008 end 2052 total 2200 skew 0 clock 33.7KHz
v: height 1080 start 1084 end 1094 total 1125 clock 60.0Hz
1920x1080 (0x4c) 74.2MHz
h: width 1920 start 2558 end 2602 total 2750 skew 0 clock 27.0KHz
v: height 1080 start 1084 end 1089 total 1125 clock 24.0Hz
1600x1200 (0x4d) 162.0MHz
h: width 1600 start 1664 end 1856 total 2160 skew 0 clock 75.0KHz
v: height 1200 start 1201 end 1204 total 1250 clock 60.0Hz
1280x1024 (0x4e) 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
1280x1024 (0x4f) 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
1152x864 (0x50) 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
1280x720 (0x51) 74.2MHz
h: width 1280 start 1390 end 1430 total 1650 skew 0 clock 45.0KHz
v: height 720 start 725 end 730 total 750 clock 60.0Hz
1280x720 (0x52) 74.2MHz
h: width 1280 start 1720 end 1760 total 1980 skew 0 clock 37.5KHz
v: height 720 start 725 end 730 total 750 clock 50.0Hz
1280x720 (0x53) 74.2MHz
h: width 1280 start 1390 end 1430 total 1650 skew 0 clock 45.0KHz
v: height 720 start 725 end 730 total 750 clock 59.9Hz
1440x576i (0x54) 27.0MHz
h: width 1440 start 1464 end 1590 total 1728 skew 0 clock 15.6KHz
v: height 576 start 580 end 586 total 625 clock 50.1Hz
1024x768 (0x55) 78.8MHz
h: width 1024 start 1040 end 1136 total 1312 skew 0 clock 60.1KHz
v: height 768 start 769 end 772 total 800 clock 75.1Hz
1024x768 (0x56) 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
1440x480i (0x57) 27.0MHz
h: width 1440 start 1478 end 1602 total 1716 skew 0 clock 15.8KHz
v: height 480 start 488 end 494 total 525 clock 60.1Hz
1440x480i (0x58) 27.0MHz
h: width 1440 start 1478 end 1602 total 1716 skew 0 clock 15.7KHz
v: height 480 start 488 end 494 total 525 clock 60.1Hz
800x600 (0x59) 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
800x600 (0x5a) 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
720x576 (0x5b) 27.0MHz
h: width 720 start 732 end 796 total 864 skew 0 clock 31.2KHz
v: height 576 start 581 end 586 total 625 clock 50.0Hz
720x480 (0x5c) 27.0MHz
h: width 720 start 736 end 798 total 858 skew 0 clock 31.5KHz
v: height 480 start 489 end 495 total 525 clock 60.0Hz
720x480 (0x5d) 27.0MHz
h: width 720 start 736 end 798 total 858 skew 0 clock 31.5KHz
v: height 480 start 489 end 495 total 525 clock 59.9Hz
640x480 (0x5e) 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
640x480 (0x5f) 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 60.0Hz
640x480 (0x60) 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
720x400 (0x61) 28.3MHz
h: width 720 start 738 end 846 total 900 skew 0 clock 31.5KHz
v: height 400 start 412 end 414 total 449 clock 70.1Hz