sample xorg.conf

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 304.60  (buildmeister@swio-display-x86-rhel47-13)  Sun Oct 14 21:19:18 PDT 2012
# This is working on 304.60 scaling
# Deprecated on 30X.X NVIDIA DRIVERS - Option                "FlatPanelProperties" "Scaling = Native"

Section "Device"
    Identifier            "Device0"
    Driver                "nvidia"
    VendorName            "NVIDIA Corporation"
    Option                "NoLogo"                "true"
    Option                "DynamicTwinView"       "false"
    Option                "NoFlip"                "false"
    Option                "ConnectToAcpid"        "0"
    Option                "ModeValidation"        "NoVesaModes, NoXServerModes"
    Option                "ModeDebug"             "true"
    Option                "HWCursor"              "false"
    Option                "SWCursor"              "false"
    Option                "RenderAccel"           "1"
EndSection


Section "Screen"
    Identifier            "Screen0"
    Device                "Device0"
    Monitor               "Monitor0"
    #Option               "VertRefresh"           "DFP-0: 23-60"
    #Option               "HorizSync"             "DFP-0: 25-100"
    DefaultDepth          24
    Option                "ColorRange" "Full"
    Option                "ColorSpace" "RGB"
    Option                "DynamicTwinView" "false"
    #Option                "FlatPanelProperties" "Scaling = Native"
    Option                "ModeValidation" "NoVesaModes, NoXServerModes"
    Option                "ExactModeTimingsDVI" "True"
    SubSection            "Display"
        Depth             24
    EndSubSection
EndSection


Section "Monitor"
    Identifier		  "Monitor0"
    VendorName		  "Unknown"
    ModelName		  "Unknown"
    #HorizSync		  28.0 - 33.0
    #VertRefresh          23.0 - 72.0
    HorizSync		  26-81
    VertRefresh		  24-75
    # 1920x1080p @ 23.976Hz (EIA/CEA-861B)
    ModeLine "1920x1080_23.976" 74.175 1920 2558 2602 2750 1080 1084 1089 1125 +hsync +vsync
    ModeLine "1920x1080_24"     74.250 1920 2558 2602 2750 1080 1084 1089 1125 +hsync +vsync
    # Remove # from below to use
    #Modeline "1920x1080_25"	74.25  1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync
    #Modeline "1920x1080_60"	148.35 1920 2008 2052 2200 1080 1084 1089 1125 -hsync +vsync
	Option		  "DPI" "96 x 96"
EndSection

Section "Extensions"
    Option               "Composite" "Disable"
EndSection