Ho due monitor:

• Acer AL1914
  con un solo ingresso
  • VGA
• Ancor Communications Inc. Asus MS236
  con due ingressi:
  • HDMI
  • e VGA

Ho due schede grafiche

• nVidia GeForce GTX 1060 https://www.asus.com/it/Graphics-Cards/TURBO-GTX1060-6G/
  con uscite:
  • DVI-D
  • HDMI 2.0 x2
  • DiplayPort 1.4 x2
• nVidia GeForce GTX 570 http://www.techspot.com/review/346-gigabyte-geforce-gtx-570/page2.html
  con uscite:
  • DVI-I x2
  • mini-HDMI

L'ordine con cui sono montate sulla scheda madre Asus P8p67 Deluxe fa la differenza, la prima è quella che viene usata di default, quindi se non è collegato nessun monitor alla prima scheda non si vede nulla all'avvio del computer/BIOS.

Su slackware la configurazione nel caso di sola scheda video GTX 570 con monitor MS236 sulla prima uscita DVI-I e AL1914 sulla seconda uscita DVI_I era

xorg.conf

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 361.42  (root@nielsabel)  Sat Apr 23 12:45:00 CEST 2016
 
 
Section "ServerLayout"
    Identifier     "X.org Configured"
    Screen      0  "Screen0" 0 0
    InputDevice    "Mouse0" "CorePointer"
    InputDevice    "Keyboard0" "CoreKeyboard"
EndSection
 
Section "Files"
    ModulePath      "/usr/lib64/xorg/modules"
    FontPath        "/usr/share/fonts/local"
    FontPath        "/usr/share/fonts/TTF"
    FontPath        "/usr/share/fonts/OTF"
    FontPath        "/usr/share/fonts/Type1"
    FontPath        "/usr/share/fonts/misc"
    FontPath        "/usr/share/fonts/CID"
    FontPath        "/usr/share/fonts/75dpi/:unscaled"
    FontPath        "/usr/share/fonts/100dpi/:unscaled"
    FontPath        "/usr/share/fonts/75dpi"
    FontPath        "/usr/share/fonts/100dpi"
    FontPath        "/usr/share/fonts/cyrillic"
EndSection
 
Section "Module"
    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 "Device"
 
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
        ### <percent>: "<f>%"
        ### [arg]: arg optional
        #Option     "SWcursor"           	# [<bool>]
        #Option     "HWcursor"           	# [<bool>]
        #Option     "NoAccel"            	# [<bool>]
        #Option     "ShadowFB"           	# [<bool>]
        #Option     "UseFBDev"           	# [<bool>]
        #Option     "Rotate"             	# [<str>]
        #Option     "VideoKey"           	# <i>
        #Option     "FlatPanel"          	# [<bool>]
        #Option     "FPDither"           	# [<bool>]
        #Option     "CrtcNumber"         	# <i>
        #Option     "FPScale"            	# [<bool>]
        #Option     "FPTweak"            	# <i>
        #Option     "DualHead"           	# [<bool>]
    Identifier     "Card0"
    Driver         "nvidia"
EndSection
 
Section "Screen"
    Identifier     "Screen0"
    Device         "Card0"
    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Viewport    0 0
        Depth       1
    EndSubSection
    SubSection     "Display"
        Viewport    0 0
        Depth       4
    EndSubSection
    SubSection     "Display"
        Viewport    0 0
        Depth       8
    EndSubSection
    SubSection     "Display"
        Viewport    0 0
        Depth       15
    EndSubSection
    SubSection     "Display"
        Viewport    0 0
        Depth       16
    EndSubSection
    SubSection     "Display"
        Viewport    0 0
        Depth       24
    EndSubSection
EndSection

Questa configurazione che fa uso di Xinerama insieme ai driver nVidia, permette di avere due schermi affiancati con una sola instanza di server X in cui è possibile muoversi fra i due monitor con il puntatore del mouse e spostare le finestre fra un monitor e l'altro. Questa modalità non funziona in caso di due schede e due monitor collegati ciascuno ad una scheda. Ad esempio MS236 sulla uscita DVI-D di GTX 1060 e AL1914 sulla prima uscita DVI-I della GTX 570. In questa configurazione abilitare Xinerama manda in crash il server X per colpa dei driver nVidia

xorg.conf

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 367.44  (root@nielsabel)  Thu Sep 29 20:51:43 CEST 2016
 
# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings:  version 367.44  (root@nielsabel)  Thu Sep 29 20:50:47 CEST 2016
 
Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    Screen      1  "Screen1" RightOf "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "0"
EndSection
 
Section "Files"
    FontPath        "/usr/lib64/X11/fonts/misc/:unscaled"
    FontPath        "/usr/lib64/X11/fonts/100dpi/:unscaled"
    FontPath        "/usr/lib64/X11/fonts/75dpi/:unscaled"
    FontPath        "/usr/lib64/X11/fonts/misc/"
    FontPath        "/usr/lib64/X11/fonts/Type1/"
    FontPath        "/usr/lib64/X11/fonts/Speedo/"
    FontPath        "/usr/lib64/X11/fonts/100dpi/"
    FontPath        "/usr/lib64/X11/fonts/75dpi/"
    FontPath        "/usr/lib64/X11/fonts/cyrillic/"
    FontPath        "/usr/lib64/X11/fonts/TTF/"
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"
 
    # HorizSync source: edid, VertRefresh source: edid
#    HorizSync       30.0 - 85.0
#    VertRefresh     55.0 - 75.0
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Ancor Communications Inc ASUS MS236"
    Option         "DPMS"
EndSection
 
Section "Monitor"
 
    # HorizSync source: unknown, VertRefresh source: unknown
#    HorizSync       0.0 - 0.0
#    VertRefresh     0.0
    Identifier     "Monitor1"
    VendorName     "Unknown"
    ModelName      "Acer AL1914"
    Option         "DPMS"
    Option         "RightOf" "Monitor0"
EndSection
 
Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX 1060 6GB"
    BusID          "PCI:1:0:0"
EndSection
 
Section "Device"
    Identifier     "Device1"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX 570"
    BusID          "PCI:2:0:0"
EndSection
 
Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "nvidiaXineramaInfoOrder" "DFP-0"
    Option         "metamodes" "nvidia-auto-select +0+0"
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "BaseMosaic" "off"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection
 
Section "Screen"
    Identifier     "Screen1"
    Device         "Device1"
    Monitor        "Monitor1"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "metamodes" "nvidia-auto-select +0+0"
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "BaseMosaic" "off"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Questo l'errore in caso di Option “Xinerama” “0”

Senza Xinerama il problema è che ci sono due server X che girano e le finestre non si possono spostare da un monitor all'latro, anche se il mouse passa da uno all'latro. In questa configurazione il desktop Cinnamon, Mate e XFCE non funzionano correttamente.

In conclusione si ritorna alla configurazione con GTX 570 come prima scheda con questa configurazione, ma senza bisogno di installere il file /etc/X11/xorg.conf

xorg.conf

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings:  version 367.44  (root@nielsabel)  Sat Nov  5 13:55:19 CET 2016
 
Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "0"
EndSection
 
Section "Files"
    FontPath        "/usr/lib64/X11/fonts/misc/:unscaled"
    FontPath        "/usr/lib64/X11/fonts/100dpi/:unscaled"
    FontPath        "/usr/lib64/X11/fonts/75dpi/:unscaled"
    FontPath        "/usr/lib64/X11/fonts/misc/"
    FontPath        "/usr/lib64/X11/fonts/Type1/"
    FontPath        "/usr/lib64/X11/fonts/Speedo/"
    FontPath        "/usr/lib64/X11/fonts/100dpi/"
    FontPath        "/usr/lib64/X11/fonts/75dpi/"
    FontPath        "/usr/lib64/X11/fonts/cyrillic/"
    FontPath        "/usr/lib64/X11/fonts/TTF/"
EndSection
 
Section "Module"
    Load           "dbe"
    Load           "extmod"
    Load           "type1"
    Load           "freetype"
    Load           "glx"
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"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Acer AL1914"
    HorizSync       24.0 - 80.0
    VertRefresh     49.0 - 75.0
    Option         "DPMS"
EndSection
 
Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX 570"
    BusID          "PCI:1:0:0"
EndSection
 
Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "nvidiaXineramaInfoOrder" "DFP-2"
    Option         "metamodes" "DVI-I-0: nvidia-auto-select +1920+0, DVI-I-3: nvidia-auto-select +0+0"
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "BaseMosaic" "off"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection