EDID I acquired when the monitor was connected by HDMI:
Section "Monitor"
Identifier "DSGR"
ModelName "DSGR"
VendorName "DSG"
# Monitor Manufactured week 24 of 2011
# EDID version 1.3
# Digital Display
DisplaySize 700 390
Gamma 2.20
Option "DPMS" "false"
Horizsync 14-91
VertRefresh 22-80
# Maximum pixel clock is 160MHz
#Not giving standard mode: 1280x1024, 60Hz
#Not giving standard mode: 1920x1080, 60Hz
#Extension block found. Parsing...
Modeline "Mode 15" 27.00 720 736 798 858 480 489 495 525 -hsync -vsync
Modeline "Mode 0" 74.25 1280 1390 1430 1650 720 725 730 750 +hsync +vsync
Modeline "Mode 1" 74.25 1920 2008 2052 2200 540 542 547 562 +hsync +vsync interlace
Modeline "Mode 2" 27.027 720 736 798 858 480 489 495 525 -hsync -vsync
Modeline "Mode 3" 74.250 1280 1390 1420 1650 720 725 730 750 +hsync +vsync
Modeline "Mode 4" 74.250 1920 2008 2052 2200 1080 1082 1087 1125 +hsync +vsync interlace
Modeline "Mode 5" 27.027 1440 1478 1602 1716 480 484 487 525 -hsync -vsync interlace
Modeline "Mode 6" 148.500 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
Modeline "Mode 7" 27.000 720 732 796 864 576 581 586 625 -hsync -vsync
Modeline "Mode 8" 74.250 1280 1720 1760 1980 720 725 730 750 +hsync +vsync
Modeline "Mode 9" 74.250 1920 2448 2492 2640 1080 1082 1089 1125 +hsync +vsync interlace
Modeline "Mode 10" 27.000 1440 1464 1590 1728 576 578 581 625 -hsync -vsync interlace
Modeline "Mode 11" 148.500 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync
Modeline "Mode 12" 74.250 1920 2558 2602 2750 1080 1084 1089 1125 +hsync +vsync
Modeline "Mode 13" 74.250 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync
Modeline "Mode 14" 74.250 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
Modeline "Mode 16" 74.25 1280 1720 1760 1980 720 725 730 750 +hsync +vsync
Modeline "Mode 17" 74.25 1920 2448 2492 2640 540 542 547 562 +hsync +vsync interlace
Modeline "Mode 18" 27.00 720 732 796 864 576 581 586 625 -hsync -vsync
Option "PreferredMode" "Mode 15"
EndSection
My xorg.conf file now:
# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 352.63 (buildmeister@swio-display-x64-rhel04-11) Sat Nov 7 22:00:19 PST 2015
Section "ServerLayout"
Identifier "Layout0"
Screen 0 "Screen0"
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
EndSection
Section "Files"
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"
Identifier "DVI-I-0"
VendorName "DSG"
ModelName "DSGR"
HorizSync 14-91
VertRefresh 22-80
Option "DPMS" "true"
Modeline "Mode 4" 74.250 1920 2008 2052 2200 1080 1082 1087 1125 +hsync +vsync
EndSection
Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "CustomEDID" "DVI-I-0:/Desktop/edid-hdmi.txt"
SubSection "Display"
Depth 24
EndSubSection
EndSection