Changing Refresh Rates

Patrick Ryan Vinson pvinson at
Fri Dec 3 04:24:31 UTC 2004

Hello Everyone,

Well, I dove into the LCD Monitor world.  I will have to say that I am
very pleased.  There is one thing though that I am trying to figure out.
The LCD Monitor that I bought, LG Electronics L1710BK, is supposed to be
able to support 75Hz at 1280x1024.  When X starts, it only goes to 60Hz.
Now, if I change the resoultion down to 1024x768 I do get 75Hz.
Thinking I would be smart and trick Xorg, I changed the VertRefresh line
to 75.0 - 75.0 just to see.  However, it ended up tricking me by falling
to 1024x768 resoultion.  I then decided, well maybe it really can't
handle 75Hz at 1280x1024 and so I did a bit more research.  However,
every spec sheet I can find on this monitor says it can handle 75Hz at
this resoultion.

My question, is there a way that I can change the refresh rate to 75Hz
or should I take that when X starts up that it falls to 60Hz a sign?  If
all these spec lists about this monitor is right I can handle this rate;
however, Xorg doesn't seem to think so.

If needed, here is my xorg.conf:

# Xorg configuration created by system-config-display

Section "ServerLayout"
	Identifier     "single head configuration"
	Screen      0  "Screen0" 0 0
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "Keyboard0" "CoreKeyboard"

Section "Files"

# RgbPath is the location of the RGB database.  Note, this is the name
of the 
# file minus the extension (like ".txt" or ".db").  There is normally
# no need to change the default.
# Multiple FontPath entries are allowed (they are concatenated together)
# By default, Red Hat 6.0 and later now use a font server independent of
# the X server to render fonts.
	RgbPath      "/usr/X11R6/lib/X11/rgb"
	FontPath     "unix/:7100"

Section "Module"
	Load  "dbe"
	Load  "extmod"
	Load  "fbdevhw"
	Load  "glx"
	Load  "record"
	Load  "freetype"
	Load  "type1"
	#Load  "dri"

Section "InputDevice"

# Specify which keyboard LEDs can be user-controlled (eg, with xset(1))
#	Option	"Xleds"		"1 2 3"
# To disable the XKEYBOARD extension, uncomment XkbDisable.
#	Option	"XkbDisable"
# To customise the XKB settings to suit your keyboard, modify the
# lines below (which are the defaults).  For example, for a non-U.S.
# keyboard, you will probably want to use:
#	Option	"XkbModel"	"pc102"
# If you have a US Microsoft Natural keyboard, you can use:
#	Option	"XkbModel"	"microsoft"
# Then to change the language, change the Layout setting.
# For example, a german layout can be obtained with:
#	Option	"XkbLayout"	"de"
# or:
#	Option	"XkbLayout"	"de"
#	Option	"XkbVariant"	"nodeadkeys"
# If you'd like to switch the positions of your capslock and
# control keys, use:
#	Option	"XkbOptions"	"ctrl:swapcaps"
# Or if you just want both to be control, use:
#	Option	"XkbOptions"	"ctrl:nocaps"
	Identifier  "Keyboard0"
	Driver      "kbd"
	Option	    "XkbModel" "pc105"
	Option	    "XkbLayout" "us"

Section "InputDevice"
	Identifier  "Mouse0"
	Driver      "mouse"
	Option	    "Protocol" "IMPS/2"
	Option	    "Device" "/dev/input/mice"
	Option	    "ZAxisMapping" "4 5"
	Option	    "Emulate3Buttons" "yes"

Section "Monitor"
	Identifier   "Monitor0"
	VendorName   "LG Electronics"
	ModelName    "L1710BK"
	HorizSync    30.0 - 83.0
	VertRefresh  56.0 - 75.0
	Option	    "dpms"

Section "Device"
	Identifier  "Videocard0"
	Driver      "nvidia"
	VendorName  "NVidia"
	BoardName   "NVIDIA GeForce 4 TI4600

Section "Screen"
	Identifier "Screen0"
	Device     "Videocard0"
	Monitor    "Monitor0"
	DefaultDepth     24
	SubSection "Display"
		Viewport   0 0
		Depth     24
		Modes    "1280x1024" "1024x768" "800x600"

Section "DRI"
	Group        0
	Mode         0666


Thank you for your time.

- Patrick

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