ubuntu18.04，双nvidia显卡时，分别接两个显示器到两块显卡，如何设在双屏？

[superheasy]

ubuntu18.04桌面版，x64，安装了两块2080ti显卡，由于手头只有两块hdmi显示器而且2080ti上只有一个hdmi接口，所以只能一台显示器插一块显卡。
现在安装了最新到450驱动，在invidia-setting里能识别到两块显卡，且识别到两块hdmi到显示器了。
但是不勾选Xinerama时，第二个显示器就显示黑屏，但是确实时在第一显示器的右边，因为鼠标移动到最右边时，鼠标可以移动到第二显示上，但是鼠标是一个黑色到“X”。
如果使能了Xinerama，那么开机显示登入画面后，输入密码后，两块显示器就全是黑屏了，但是这个时候时有鼠标的，而且可以在两个显示器间移动，而且鼠标都是正常到样子，就是全黑屏。。。
请教，应该怎么设置，谢谢～～～

配置如下
sudo vim /etc/X11/xorg.conf


# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 440.82

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 450.57

Section "ServerLayout"

# Removed Option "Xinerama" "0"
# Removed Option "Xinerama" "1"
# Removed Option "Xinerama" "0"
# Removed Option "Xinerama" "0"
Identifier "Layout0"
Screen 0 "Screen0" 0 0
Screen 1 "Screen1" 1440 0
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
# Option "Xinerama" "0
# Option "TwinView" "1"
EndSection

Section "Files"
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 "ViewSonic VA1948 SERIES"
HorizSync 24.0 - 82.0
VertRefresh 50.0 - 75.0
Option "DPMS"
EndSection

Section "Monitor"

# HorizSync source: unknown, VertRefresh source: unknown
Identifier "Monitor1"
VendorName "Unknown"
ModelName "ViewSonic VA1948 SERIES"
HorizSync 24.0 - 82.0
VertRefresh 50.0 - 75.0
Option "DPMS"
EndSection

Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce RTX 2080 Ti"
BusID "PCI:2:0:0"
EndSection

Section "Device"
Identifier "Device1"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce RTX 2080 Ti"
BusID "PCI:131:0:0"
EndSection

Section "Screen"

# Removed Option "metamodes" "1440x900_75 +0+0"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "Stereo" "0"
Option "nvidiaXineramaInfoOrder" "DFP-2"
Option "metamodes" "nvidia-auto-select +0+0"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
Option "TwinView" "1"
SubSection "Display"
Depth 24
EndSubSection
EndSection

Section "Screen"

# Removed Option "metamodes" "nvidia-auto-select +0+0 {AllowGSYNC=Off}"
# Removed Option "metamodes" "1440x900_75 +0+0; nvidia-auto-select +0+0 {viewportin=1366x768, viewportout=1440x809+0+45, AllowGSYNC=Off}"
# Removed Option "metamodes" "nvidia-auto-select +0+0 {ForceCompositionPipeline=On}; nvidia-auto-select +0+0 {viewportin=1366x768, viewportout=1440x809+0+45, AllowGSYNC=Off}"
# Removed Option "metamodes" "nvidia-auto-select +0+0 {AllowGSYNC=Off}"
Identifier "Screen1"
Device "Device1"
Monitor "Monitor1"
DefaultDepth 24
Option "Stereo" "0"
Option "nvidiaXineramaInfoOrder" "DFP-2"
Option "metamodes" "nvidia-auto-select +0+0 {ForceCompositionPipeline=On, ForceFullCompositionPipeline=On, AllowGSYNC=Off}"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
Option "TwinView" "1"
SubSection "Display"
Depth 24
EndSubSection
EndSection

Section "Extensions"
Option "(null)" "Disable"
EndSection

[astolia]

xinerama都是多少年前的过时东西了，早就都转向xrandr了。n卡闭源驱动我记得支持xrandr都很久了。可以安装gui版的arandr来设置
另外TwinView可能会和xrandr的设置有冲突，我没用n卡不太清楚